I'm using karbonn A12 from past 10 months, The day i have bought the mobile itself i faced heating problem, while we access internet in 3G it gets heated and the phone automatically getting restarted frequently.
Battery backup is quit normal. Camera quality is very poor,Even though it has 5MP with LED flash, The phone captures picture like a 3MP cam.
Frustating moments when i installed the subway surf, Game is moving backward while running, But temple run works fine..
Last few month before I bought this mobile, everything is good like display, touch speed, processor speed, Jelly bean os and battery backup.
Only thing is Flip cover & silicon cover is not available so far. rest everything is SUPERB.... I really recommend this to my friend