I will say that ASUS ZenFone 2 is better than both the other Google's phones.The most important reason is the price of ZenFone 2 which delivers a high end smartphone's performance as Samsung
galaxy s7 delivers.In fact i am using ZenFone 2 ze551ml model from last two months and seriously i don't find any problem related to software or hardware yet.Its have 4gb ram clocked at 2.3 ghz quad core intel processor.I played Gta sanandreas, Modern Combat 5 and many other graphically immersive game on it at maximum settings and i don't find any lag.The battery performance also so impressive which i can't avoid to tell.So
over all my choice is definitely ZenFone 2.