What prevents me from adopting XMPP for my team is the lack of push notifications to my phone. I don't want to have an app constantly maintain a connection and slowly drain my battery.
The Conversations app for Android works pretty well. I've used it for a few weeks with a handful of persistent rooms on a Nexus 5 and I haven't noticed any battery issue.
Some years ago I built an Android SDK that did background location and had an XMPP channel open for push notifications. This was before Android had Cloud Messaging available. Battery drain was minimal/negligible.
