Since 6 months I have been using iphone 4s. efficiency is good. im using the mobile with 8gb internal memory. I found of selfies. Camera is damn good. remaining features like itunes, icloud, ibooks etc. r good. The only draw back is it doesn't support 4G. Definitely u should have WiFi connection to use all the apps efficiently. U can review stock exchage updates like Sensex, NIFT.