1.Consuming too much power and affecting battery life.
2.Scrolling is very noisy so need too much repolish user interface.Project butter isn't works. Every application is not smooth e.g - in clock move from world clock to timer breaks, home screen, gallery, slide show is bad.
3.Some applications run in background always live in notification bar eg - Uc Web background download always shows in notification bar "Uc Web is running tap to more information "
4. Bugs with Blutooth, wifi, nfc
5. With this operating system applications run problematic not perfectly like chrome
6. Old camera UI was excellent - excellent..look and functionality.New UI looks very very bad and decreased quality.
7.Problem with video recording.
8. New Keyboard app is very very bad We want old keyboard.
9. Ram management is bad.