Ask me lar. I always used both iOS and android.
My fair opinion. After using V20, I almost feel like leaving my iphone 7+ at home. If not because clash of clan game(left hand request, right hand donate troops), I'll only bring V20 out. But I need to play multiple accounts, so both V20 and 7+ bring out. Now, my heart is toward ZenFone 3 ultra for gaming. But definitely V20 will be my primary device. Dunno anyone had opinion about z3 ultra? Me read thru the whole ZenFone thread, never gain much pros and cons from there apart from no NFC.
PS: I feel the new fusion processor from iphone 7/7+ is not perfect, maybe serious flaws? Occasionally will freeze for few seconds, I encountered few times need to force restart because the whole phone not responding. That happened in 10.0.2, 10.1, 10.1.1 too! My guess it's hardware cos the freeze happened in all 3 firmwares. Dun think it's due to me having lemon set because I've got total 5 iPhones 7/7+ within my family. 3 sets had freeze issues.
Edit: someone from iphone forum encountered too.