^^Well, I have mine in hand today. And the first thing I notice is, my M2 is not recognizing my Idea sim in the sim slot 1 (didnt check in slot 2). Slot 1 recognizes my Airtel sim without a problem.
(Slot 1 is regular mini sim and slot 2 is micro sim).
Initial impressions :
The phone is solidly built, has a huge huge battery (which I am trying to caliberate now). The battery being so big, the phone is very heavy.
The User Interface (Amigo UI as Gionee calls) is pretty sluggish, slow animations everywhere, everything is heavily themed. They tried making it similar to MIUI, but the implementation is nowhere even close. The gallery app is useless with not even the basic functionality covered. Has tons and tons of bloat.
The screen is pretty okay, gets the job done in other words. Coming from a moto g , lumia 920, the resolution difference is very much noticeable.
The audio output via the 3.5mm audio jack is infact very poor. Also it has no built in equilizer. Not all headphones are supported as well.
The in call volume is good, though the quality isnt all that good, distorts quite a bit.
While the UI is poor, the actual operation is actually quite good. Opening apps, switching between apps, web browsing etc are really good with no problems.
These are my initial observations, totally based on my personal usage type. Will be rooting the phone and installing Xposed mods in a few days whenever I get time (21st and 22nd of this month mostly).
Dont get me wrong, the phone is actually very well worth the money, the touch response is excellent for its price range and competetion, the battery is pretty much unbeatable, built is very solid and doesnt feel cheap in hands in anyways.