Reply bug in the "new" (beta) outlook that I found immediately:
When replying to all attendies of a meeting, it fails to allow scrolling of the reply. This causes the area into which you're typing to be hidden behind the keyboard, so you can't see what you're typing! To get around this I had to type it in another app, then paste it into outlook. Even then, I could scroll down to see my complete reply.
This does NOT happen when replying to regular emails, only when replying to all meeting attendees.