I've got the regular S2 for a couple of weeks now. It's a good phone with some downsides. Camera is not fantastic but good enough for everyday stuff. If you want amazing photos buy a flagship. Proximity sensor doesn't turn off screen properly while in a call, maybe fixed in future version. One of the major networks in Germany does not work for mobile data in most cases (O2 and Eplus joined and the phone can't handle the "data roaming").
Tech support is non existant. They will point you to their half chinese forums with barely any members that is spammed with press releases. Posting takes dozens of "money" that you must unlock with posts. Very unprofessional but maybe expected for such a relatively small company. There are no service addresses for repairs and the accessories market for that phone is very very limited. Barely any cases or screen protectors out there. If you break anything on this phone expect to get a new one. I have not tried yet but to get replacement parts for this seems near impossible at this point.
Other than that, screen is great for the resolution. Battery life is absolutely brilliant. I can get through a full day with using <40% battery and it lasts easily 3+ days on pure standby.
Wifi has become much better I think after the last firmware update. They are updating the phone but I wonder for how long. This is not a manufacturer that can or wants to support all of it's devices like big ones do.
Materials are good, maybe a bit slippery in the hands but all microblasted aluminium phones are like that.
Screen has a <1mm bezel between the side of the phone and the display surface but I don't care about that.
Build, to me, feels very good. Fingerprint sensor works well and fast. Android is 6.0.1 but I hope they will have an update to 7 or 8 at some point.
I don't care about benchmarks so I can't talk about that, my apps work well. Video streaming is fluid. No idea about 3D gaming I don't use my phone for that.
For that price it's a great phone imho.