I am using this mobile from 3yrs not event a single complain even doesnt lag till now many mobile came in market and gone but am still stick to it cause it really very good mobile with average battery backup it will alive for 12 to 13 hour with normal usage if using internet through wifi or data it will drain much faster.
Till today lags are very rare when more application are open its come out of that application but doesnt stuck any were, sound in headset is good, camera is worst, speaker sound average, connectivity good.
The product is good for it price.