You have to play on Normal to unlock Professional, so it'll take 3 runs to complete the game if you start on Easy.
Originally Posted by Creech
As a site, we don't support calling it "xbone" as that was a name that was used to refer to the system in a negative light. Since the site exists to support the system, being deliberately negative towards it seems counter productive.
tl;dr - Call it the Xbox One or X1.