At the risk of being mauled, we keep hearing about what a great athlete Bates is, but I for one haven't seen that much from him yet. He made one clutch play last year against an overmatched linebacker. Other than that he really didn't do anything.
I understand that he is a good athlete, and he has an edge over Arnaud in that department, but I just wonder if people are making more of this advantage than actually exists. If I remember, Arnaud looked fairly mobile as well, its not like he's a sitting target. Personally, I think that Arnaud is athletic enough that the decision should be made solely on the QBs passing ability and ability to run the offense. If that's Bates, I'm fine with that. If not, and Bates is really as athletic as he's hyped to be, I'm sure he'll find the field in some other capacity.
With all that said, both QBs sound more than capable, and I too will be happy with whichever QB is chosen.