This is a fast flexible cube with great corner cutting, and still very controllable. The magnets are strong and help control the cube.

Amazing. Out of the box it was not amazing. But after tensioning it and lubing it was a main killer.

Setup:
Similarly to most moyu cubes, this cube works well with a variety of lubricants. Out of the box, the tensions were pretty loose, but at least they were even. I tightened it about one wrist turn, which worked pretty well for my turning style. I would recommend setting the spring compression to the 5th or 6th click. This creates a fast yet controllable feel. I lube the spring and screw with weight 4, as well as lubing the tracks of the pieces with weight 4. For a piece lubricant, I would recommend a lower viscosity lubricant, although I also found weighted lubes to work fine. Now, break in!
After about 100 solves, this cube is AMAZING. Although this is a slightly older cube, it still beats modern flagships by a huge margin.

I'm new to the magnetic scene, but I'm wishing now that I'd be on board a long time ago. This is a great cube! It turns fast and smooth without any setup. I nearly set an unofficial PB in the first couple days of having it.

I actually meant to put this review for the aosu wrm 4x4 so you can just ignore that review

This cube is very nice and super fast out of the box. My first solve on this cube was, at the time, my personal best. its a bit loud but if you like that clacky sound this is a great cube.

The GTS3M is quite possibly the best cube I own. Out of the box it was pretty fast, clacky and there's a lot of spring Noises coming from each side I turn. The tensioning system is phenomenal and the ridges don't bother me at all, they're quite cool. Overall this cube is great. Although it's not very budget friendly I think this cube is good for all stages of cubers.

This was the first cube I got after getting back into speed cubing for a year or so. I was really excited because I missed the transition to magnetic cubes and this would be my first one. It was alright out of the box and was kind of dry. I eventually lubed it with some weight 4 and mystic because I love when a cube is almost uncontrollable.

It has been working amazing, even after a couple drops. The worst part is, though, that I can't easily and justifiably buy a new cube. The feel is amazing and the ridges aren't noticable after a solve or two. I can't complain much with the cube and the only problem I have is that it's hard for me to be a smart and logical collector.

10/10 would recommend

First I need to ventilate a bit about setting up the cube.
Out of the box the cube was uncontrollably loose and fast. After watching J Perm's video it was possible to set up, and once you know how, it's very easy to change the spring tension of the cube. But on my cube the springs were also rather noisy. I had to take it apart completely and lube the inside of the spring houses and then it became better, but I do need to run the cube on a looser and faster setting than I prefer to mitigate the problem with the friction on the springs causing noise. I was running the spring tension system on the firmest setting first (8) and now I'm down on 7. I guess that in the long run, I will benefit from learning that as I should be faster once I learn better control. The cube needed lubing as it it was very dry out of the box.

About the cube itself.
I like the ridges and after setup the cube became very nice. I'm still breaking it in but I have high hopes for it. The magnes have a good strength and all in all I'm very happy about it.

My first solve was a pb. I got a 6.825
It is so smooth and lockups rarely happen
It is very fast as well

It comes in a nice magnetized container. Inside, there is the cube, its display stand (which is really high-quality and perfectly sized for the cube), and some tools for the spring mechanism, which is actually really good. I use spring setting seven, and I really like the cube. After a solve on it, you don't notice the ridges anymore.

Out of the box, the cube was very loose, but it has many ways to customize it to make it perfect. I put it on the 8 setting and tightened it a bit. After a few months of breaking in, I enjoy solving on this cube, much more than on any other cube. With a bit of breaking in and setup, this cube could easily become anyone's main

This cube is a perfect gift, but make sure you don’t put in lubicle black because, if it is possible, this cube is too fast so keep that in mind!

I set it up in about 15-20 mins with weight 5 in the core and weight 1 on the pieces. I then watched JPerm's video on this cube to explain the spring compression and tension differences. The next day I got a 8.4 which was my new PB by 0.4 seconds. Great Cube!

This cube fixes all problems with the 2m. The cube feels amazing and Is a worth upgrade from the 2m.

After nearly 2 months of occasional use of the GTS3 M, I find I still prefer the GTS2 M. The magnets seem to be too strong for me and break up my rhythm. I like the tensioning system.

The tensioning doesnt really matter, because you can change it in 5 minutes max, but it was really dry. Overall, its magnets were not as strong as i expected, but its corner cutting and turning were great.

SHIPMENT:
The time it took from my order to the delivery to germany took 19 days (incl. custom).
The support answers your questions in a decent time frame ( mostly 2-3 days ).
Sadly the USPS Shipment information tracker seemed to be a bit glitched...

CUBE:
Cube wasnt damaged. Nothing was missing.
Right out of the box the cube felt kind of dry which isnt really a bad thing
because you are able to lube the cube how you want it to be.
The tension was okay, but the screws were not tight enough (for my turning style).
It was also pretty fast:
U2‘s were easy possible with just turning it once with a little force (still possible after tighter tension.
However overshooting doesnt really happen in my solves).
Honestly I didnt notice the ridges when I did some first turns. While solving it now it doesnt bother me either.
In my opinion the magnets are the perfekt strenght to hold the cube together.

I got the Gts3m about a week ago and I have done about a 1000 solves on it. The gts2m was my main for every event and my all time favorite cube so I was really excited for the 3. However when I got it it was very dry and badly tensioned so I took some time to set it up with weight five and some angstrom lubes. The cube became better but I still can’t find the right elasticity/tensioning combo that really works. Also I don’t like the ridges all that much and not the magnets very strong feel. I still am going to try to use this cube and explore to see if I can make it good but for now it is not my main.