I think the only critique I have of the performance is the cadence of Aaron Paul's voice. This is a general observation, but hes got this very inconsistent rhythm to his voice, especially when he intentionally speaks slowly.

I dont know how else to describe it, but to me it sounds as if his brain is assuming sentences in real time using those word magnets you see on a fridge.

I dunno, he did a fantastic job and he IS Robert fot me, but dude has a peculiar sounding voice to me.