To me, it just further pushes two key aspects of regular email... (1) Never delete anything and (2) Grouping of message types (as was rolled out with Category Tabs). I'm trying to commit to see if it works for me but it goes against my own mentality of (1) deleting what I don't need and (2) organizing what I do keep into specific custom labels/folders (which you can still do, it just takes an extra tap compared to GMail.

Funny thing is now I'm using GMail for Exchange and NOT for GMail.