Side By Side Comparison of Oppo U3 and Asus ZenFone 2 ZE600KL. Compare Processor, display, RAM, Storage and other features here. You can quickly compare Oppo U3 and Asus ZenFone 2 ZE600KL smartphones just by looking at their ratings and results showing "winner" and "runner up." There is also a short analysis comparing different features of Oppo U3 and . You can also look at each hardware feature individually to perform your analysis while comparing mobile phones.