In your case scenario, my Nexus 5 gets 20 hours of on screen usage.
Really? Do me a favor and call anyone that only owns an iPod or WiFi iPad. You are probably going to run into a little trouble sending all these people an iMessage or Facetiming them. You know, cause they don't have a phone number associated to Apple. They DO HAVE an email/Apple ID associated though. See any issues with your comment now?
iMessage and Facetime requires the following:
1) An Apple account
2) Tie a phone number or Apple ID to that account
3) Requires another user to HAVE an iDevice or Mac. Can't be used outside of Apple's ecosystem
4) Manually initiate a Facetime call or iMessage
5) Does not collate Facetime or email or SMS into one thread (after years and years of development, Apple still can't collate Facetime and iMessage together?)
As noted above, this information is incorrect.
Google will never go where Apple is with iMessage/Facetime. To restrictive and not open to all platforms. Hangouts is platform agnostic, as Google apps should be.
You are correct on visual voicemail. This should be added into the phone api at some point, since that is closed source it can't be messed with by the carriers or oem's.
Wow, please stop. iMessage and FaceTime ONLY require a phone number, obviously we're not talking about iPads and iPods.