I've noticed this delayed notification issue for the past 2 years now, so it's not just the Nexus4. On Android Gmail and Google Voice are late about 75% of the time. Late as in 2-20 minutes after other devices get the messages. The sad part is that Google's own Gmail app, not Exchange, but the Gmail app from Google for iOS will always get the email first...even faster than it shows up in the desktop Chrome browser sometimes. This also is the same for the Google Voice app on iOS...I don't get why this is at all. Sure some messages will push and arrive almost immediately, but never faster than the desktop browser or iOS apps...but more than often, they will show up a minute to 5 minutes later, if not even longer. Send yourselves a few emails from another account to test this out. Don't even get me started on the new GoogleMaps on an iPhone5, it seriously is better than the Android version.