Unfortunately, mine had a defect - some of the corner magnets had either not been glued in or dislodged from their slots. In fact, one managed to fall into the center hole leading to the corner-center magnet, making it impossible to remove. I don't think this is a common issue, but I am including this information as a warning for other buyers. Now onto the actual review:

Although the performance of the puzzle was fine, I personally did not care for the feeling very much. The puzzle feels light and somewhat papery once set up. Unfortunately, I didn't like the feeling (if I get a replacement, I will try a different lube setup) and the magnets were a bit too snappy. The start/end of a turn is very abrupt and that threw me off a lot while solving. This was not helped by the fact that I use the Roux method; the M slices were pretty tough to do properly during LSE.

I give this puzzle three stars because of the defect. If not for that, I would probably rate the puzzle four stars because I think that this was simply a puzzle that does not match my turning and feel preferences. I suspect that other cubers would like it and the performance is perfectly fine.

Just like the gan 11 m pro but cheaper and lighter.

Let me start off by saying that this is an excellent cube. The performance is great, it has a unique feel, and finding a cube with a better combination of stability and corner cutting would be pretty hard to do. BUT, I would not recommend this cube to beginners. Yes the cube is expensive, but the main reason I am saying this is because of how difficult it is to set up well. Even though the Gan tensioning system isn’t too difficult, finding the right combination of settings to work with lubricants was something I found very difficult. Cubes like the RS3M work with virtually any lube, and will likely perform pretty well regardless of what lubes you have. The Duo however seemed to have a lot of trouble working with most lubricants. It was incredibly easy to over lube, and even versatile lubes like Martian, Gan lube, and Silk all seemed to be pretty mediocre with the factory tensions. The only single lube that I found worked well was Mystic, but even that had to be mixed with a little DNM to work well. This isn’t a big deal for cubers who have a variety of lubes and are experienced with trying out different set-ups, but for a new cuber, or someone who doesn’t have a lot of lubes to use this could be a big problem. Plus, the cost of the cube makes buying lube for it even more expensive. For this reason I would not recommend it for cubers that don’t have experience setting up puzzles or don’t have a lot of lubes.

If you want to get a 11 M pro, get this instead if you think oh this cube is too old, maybe it is but it is just so amazing I have the GAN 12, 13, Tornado V3, this has just stayed my main if it's to expensive the baseline Gan 11 M is also amazing (just dont waist your money on an 11 M pro) I don't recomend the 11 Air for its price. i did not buy this cube from the cubicle but this is for all the users of the best online cubing store!

This cube is great, it has good corner-cutting, is quite stable, and has a good tensioning system. The problem for me at the beginning was how strong the magnets were and I had trouble finding my preferred tensions. I think that only having 4 center travel options isn't enough, I was constantly torn between setting 2 and 3 but eventually, I landed on 3. After setting it up with mystic and angstrom lubes it feels great and I have been able to get used to the magnet strength. This cube has definitely improved after break-in and is now much smoother and the corner-cutting has improved. It's now my main and I have broken my PB single with 2.78 on this cube along with getting my new PB ao5 of 5.87. I would give this 4 and a 1/2 stars but that isn't an option.

EDIT: I've been using this cube for a month now and all I can say is that its performance is really inconsistent. The first couple days of the cube were extremely delightful, I thought the cube was the perfect cube for me but after a while, it gets weird with its magnet strength and you need to play with the lubing, tension, and all to fix it. In my honest opinion, this cube performs better without any lube; though I still wouldn't suggest playing with the cube with no lube since lubing a cube helps extend the quality/life-span of a cube & this cube is expensive as hek

This is my first Gan cube and it is awesome. It moves so smoothly and it has so many different settings that I can costumize. Overall this is a great cube for the money

The cube is good for a flagship cube, it is like the gan 11m pro and it's so light and good!
Also, it uses the GES pro!

This feels great I like this as much as 11 m pro and it 20$ cheaper. The only thing that the 11 m pro has and not this is adjustable magnets. The magnets on this cube feel like number 2 on the 11 m pro. Personally I like 2 the best on the 11 m pro 1 is floppy 3 is supper weird.this cube comes in a shiny box (like the 11 m pro) and has gans ges pro system in addition it has core magnets. Would highly recommend. Peace fellow cubers ✌️

GAN 11 M Duo 3x3