As a big GVS fan, ARMS is exciting as it does bring 3D arena fighting more to the foreground. It's also fun because of its limitations in comparison to GVS. In that game, you have long range/close range options, cancels, formations, assisting your partner, need for more spatial awareness, lots of mobility and so on while being centered around 2v2 team gameplay. ARMS has effectively ripped out half of that, but still manages to be intriguing and scratch that itch. It does make me wish there were more close range options though, like if we could coil up our arms for some quicker short-range multi hitting combos or something like that.
And if you guys have any passing interest in gameplay similar to ARMS, please check out our Gundam Versus thread as the main series is finally coming stateside and they are currently running a trial version this month similar to the Testpunch:
http://neogaf.com/forum/showthread.php?t=1383438