Hi.i am using asus zenfone 2 I dont have a single problem.bettery beckup is very well it have 3000 mh lithium bettery.camera is good.in this mobile 2 slot of sim boths are 4g lte system is very fast.no any hanging problem in this mobile.easy to use and design is very slim and it is black touch screen so itz look very sexy and shiny.we get one more benifit back cover is scretchless and rubber cotted that way we dont get any scretches.And sound qualityis very nice.touch is very smooth.