I rode the route today. I thought it was awesome—thanks a lot to the creators. The GPX file seems to be working fine so far. A few more comments on the previous ones:
Yes, at the start of the descent, you ride briefly through private property. The hiking trail goes through there too. There was no one there today (Ticino is just waking up from hibernation), and even if there had been—a quick “Buongiorno” would have settled everything.
Difficulty is always a matter of opinion; in some places, a 4-point rating would probably be appropriate. On the other hand, you should have a reasonable idea of what you’re getting into when you’re riding a bike on T2 hiking trails.
I didn’t come across any stairs leading to “nowhere” where you have to carry your bike back up.

We started in Cugnasco, a start from point 451 at the contour line would be even better, so you don't have to drive up and down the tarred road. Otherwise a great tour; very demanding in parts, but fun. Start not on the hill but at the last hiking trail arrow before the bench, then it fits tiptop.

Today I chose this tour for the end of the day.
A good climb up to Monti di Ganna, pleasantly steep but still a bit of a drag!
When I arrived at the top, I first took a little breather on the beautiful bench. Then it started... Trail search, the entrance which is on the GPS file, is through a private road, which is closed by the owner! I then just went around the outside (quasi straight down from the bench!) but then I stayed in the private area, luckily nobody was there! Then I went through the second private property and kept right! And then you find the hiking trail. Now we really got going! The trail is quite technical, from top to bottom... (the rain certainly contributed to this) quite a lot of stones, but for me it was actually easy to ride. Except for one place, (hairpin bend with heavily blocked stones) otherwise I could ride everything! However, I can imagine that not everyone can get down there without problems!!! I.e. it is technically a 4 for sure! And you have to feel safe on the bike!!!
When the trail was finished I continued to follow the GPS file! Strangely enough, it led me down a staircase (not rideable), then I ran down and realized that it was impossible to continue! Carried the bike back up, continued on the road to the end, there is another private road where you are not allowed to go through! However, there is a gate that leads into the vineyards! Studied the map and saw that this is a possibility! And so it was true... Pass two gates and then left through another gate, then down the stairs and you come back to the road, then right and all along the road back to Gordola.

It took me 2 1/2 hours for the whole route but without a long break.

Conclusion: Trail rideable even after the heavy rain, but technically not without! You shouldn't just go for it, but look at one or two places before riding them. Overall a fun ride with a few challenges.

Ride on...

Ridden on 22.07.2023.
Trail in very good condition. Bagger is gone and the small middle part is flowy. The upper section is technically demanding, the middle section is more technically challenging after the flow and before you reach the ascent road, it gets technically action-packed again.
Great trail...but not for people who overestimate themselves...I wish them a lot of fun while running.
At the lowest part we destroyed the meters of altitude with many stairs. :-)

We rode the tour at the end of May.
It wasn't dredged any further, everything is fine.
The problem with the trail for some will be that it is narrow and sharp in places and there is a lot of loose rock lying around. That doesn't suit everyone

We rode it on April 15, 2023. In a middle section, the trail was unfortunately dredged to 2m and rolled flat. It was still only a short section, but the excavator was still there and I fear they will continue. It would be a great pity for this beautiful trail!

Great trail in surprisingly good condition as there is almost no foliage. The trail requires some courage and very good brakes. It has steep, stepped, blocky sections where you have to let the bike go and then brake down again on a short stretch of loose ground. This is perhaps the reason for the discussions about the difficulty - some people like it less than others. Compared to Carbon Trail and Corona di Pinci (same rating), I think the rating is correct. Incidentally, all three are rated on Trailforks with Black Diamond, which shows that 3/6 does not mean easy.

Cool trail, we rode it yesterday on 25.2 in fantastic weather. It's completely snow-free and easy to ride. We don't quite understand the whole discussion here... There are no trails that only have 3 or 4 point ratings. Sometimes there is an easier section, sometimes there is a challenge. That's what makes nature trails different from those boring flow trail highways. The trail requires a certain amount of skill, but is super fun to ride and great fun. A few hairpin bends and loose rocks shouldn't stop you from riding this cool trail!

It was definitely more than riding technique 3, even by Ticino standards. The upper part was more like 3-4, the lower 4-5.

I've been riding bikes for many years (Finale, South Tyrol and all the spots in Switzerland where I live). I'm not a crack but technically not that bad. Personally, I think 4 is better than 3. In any case, another tip. If you often have problems in the upper part and have to descend, you should definitely skip the second part. It doesn't get any easier and is more of a run that is not much fun.

After an extremely dry winter, the trail is currently passable without any problems.
On 2.3.23 there was neither snow nor mud, but rather dust and lots of slippery dry leaves.
My impression was that someone was maintaining the trail: large sections had been cleared of leaves and cleaned up so that the line was clearly visible. Good job! Thanks to the hard worker!

Personally, I think the difficulty level is 4 rather than 3 as indicated by RIDE. Due to various spots that have been washed out much more over time by rain, logging and use than was the case a few years ago.
A solid riding technique and courage are an advantage. Flow trail is different. As already described by other users, a typical Ticino trail.

Luckily I rode the trail yesterday and didn't let some of the comments here put me off. I usually ride trails from Ride that are rated 3-4 riding technique. For this trail (from the start to Curogna) I think 3 riding technique is just right, it's even one of the more flowy trails in Ticino. Sure, it has three key sections and, as usual in Ticino, lots of loose rock and foliage. Super pleasant ascent.
Thanks to beatungricht for the suggested variant via Monte Motti up to Fopiana and then down via A Grosseca, very worthwhile! If you still feel like it from Curogna, you can ride back up to Monti Ditto and from there take the trail on the left just before the village entrance. However, this is a 4/6 riding technique, the trail can be found on Trailforks (Dittotrail).

Trail can currently (15.01.2022) be ridden, is snow-free.

I rode the trail yesterday - with an extension: ride to the other side to Monte Motti and further up to Fopiana. There is a good trail (marked red in Ride) via A Grosseca to Gana - and then add this trail. 1480m, about 3:30 hours.
I would like to make two comments about the ride markings, because I have ridden almost everything that can be ridden in the Sopraceneri: Red doesn't mean flow trails without demands and black means: tough challenges. Both can be very different. For example, the southern part of this trail (Arünch-Colett) is much less challenging as a black trail than the black trail down the Serta to Quartino on the other side of the valley. Markings are good indicators. On the spot, you have to face the challenges you encounter. Seen in this light, I can't quite categorize the comments here. The ride team provides an assessment. Whether I can implement this with my technical riding skills is my challenge and responsibility.

The rating of the trail does not match that of other trails in Ticino. Corona dei Pinz, for example, is also rated 3 out of 6, but is much easier to ride. Or someone clears the loose stones the size of soccer balls out of the way ;-)

The upper section is almost continuously rideable for good bikers. You should love hairpin bends, then it's fun. The lower section is not recommended even for good bikers. Many blocked sections and loose scree force even good bikers to hike. The route was ridden with Race Fully. Due to the scuff marks on the large stones along the way, one or two bikers have already damaged a rear derailleur. I ride black routes in bike parks without any problems, but the lower part is only for the really crazy ones. Agree with peyou_40825, the lower part is double black. After a week in the mountains of Locarno, I realized that various route descriptions are wrong and that we keep coming across bikers on the trails who are completely overwhelmed by the terrain. In my opinion, it is negligent to describe trails on which every second rider has to push their bike as flowing. With the advent of e-bikes, more and more technically inexperienced bikers are out on the trails and have to push the 20 kg bike.

It's already quite rugged. The trail is nice but not great. More of a "training lap".

I can only agree with Sarah here. The trail is easy to ride throughout, with a few key sections that are neither exposed nor dangerous in any other way. All in all, it's a trail for practising - and not one where you absolutely have to be able to ride. Technicians are certainly better served by the Monte di Motto.

So I can't agree with the comments. There are certainly technical sections now and again, but they are by no means unrideable. You just have to be aware that you're riding in Ticino :-D
All in all, a super flowing trail which is great fun.

Wonderful ascent on asphalt. Downhill in the upper part 3, below 4-5 with many walking passages!

The tour is incorrectly rated 3 in the riding technique. On Trailforks this descent is rated as Double black diamond, which is more correct. An adjustment on the part of Ride would be good !!!

I can only agree with Berni's comment. Beautiful tour with fantastic Ticino villages and a few very nice viewpoints. However, the 3 in riding technique is definitely too short. The lower part requires a lot of downhill hiking or you really have to be an enduro crack.

Very nice tour. The trail may be a bit "rougher" now shortly after the winter, currently a good 4/6 (riding technique) - some technical sections and the ground is quite loose in places. I've ridden much "easier" 4/6 ride tours.