Bucky Brooks is pretty good, but I think that write up is a lot less rosy than it appears to a Broncos fan looking for reassurance. This is the second paragraph:
From a critical standpoint, I questioned his game-management skills and diagnostic ability, somewhat due to his limited high-level reps. He wasn't tasked with a lot of responsibilities at the line, and he looked like the kind of prospect who would need some time to master the nuances of the position as a potential NFL starter. Additionally, Osweiler underperformed in big games at ASU, leading to questions about his immediate potential as a franchise quarterback.
The remainder of the piece is speculation based on preseason action, which is about as useful as ... well preseason action. Yeah, Osweiler has shown something in preseason action and garbage time.
On the plus side, Brooks comped Osweiler to Matt Schaub, who was perfectly cromulent in Kubiak's system. But the key is the bold - he will need time to develop, he lacks game experience, he hasn't run a complicated offense, he played poorly in big games.
Brooks gets paid to write stuff that gets read, and Broncos fans will read, and like, what's in that piece. But to critical readers, that 2nd paragraph is Brooks's real opinion.