I watched almost every Clausen game this year so my opinion of him is based on the way he performed on the field. I feel like he has the arm, he's very acccurate, he can change arm angles to adjust to throwing lanes and maintain accuracy, he comes up big in the big spots and his performance stays consistant regardless of the opponent.
One of my best friends is a college OC at a very good school and he DVRs all of ND's games because he like to see Weiss's offense and how it adjusts from week to week. During the season he called me on a Sunday after ND played USC and said that Clausen had one of the most impressive games that he's seen out of a QB in a long time. He could not believe how he hung while his Oline played like crap to make throw after throw. By the end of the season he said that Clausen was the best QB that he's seen in years. There are two thing that he's pointed to, his ability to make every kind of throw regardless of context and the way he plays mistake free regardless of the opponent/situation. In his word, that shows he has the "mind & body".
If Clausen is there and the Bills pass, it will be yet another setback for a team that can't figure out the draft. I know NGU's track record is stellar but let's hope he's dead wrong about this.