Well, if you want the short answer, yes, it is. If you want to read why, in my opinion, this is one of the best speedcubes nowadays, keep reading.
Despite its age, this cube holds up really well against the more newly released WRM, the GTS2M is a ver fast and smooth cube, no bumps along the turn. It has a very clacky and snappy feel. The corner cutting is really good, if tensioned well, it never pops. I first got the GTS2M back in 2017, and I got my first official sub8 single and sub9 average on it. I have won many competitions with it, and nowadays, despite using the WRM as my main, I still pick up the GTS2M regularly, and I get the exact same times as with the WRM.
I highly recommend the GTS2M.