[the_watcher]

I like that they've done with Messenger. All they did was make an app specifically designed for messaging and remove the bolted on version from the main app. You shouldn't notice any UX differences once you install the new Messenger app thanks to the wonders of deeplinking.

[ionforce]

I guess this matters less and less as old phones get phased out, but I think there is some memory overhead in having two apps rather than one. Like if you switch apps and then the reaper elects to kill your first app, the switch back isn't so nice. Whatever, edge case.

Another UX edge case is when you hit Messenger directly, there's no backlink to Facebook. That's kind of blah.

[the_watcher]

Yeah, that is irritating, but when the deeplinking to Messenger first started, there was never a backlink to the Facebook app. That's changed, and I bet Messenger will too.