Since the Bills franchise has been in the toilet for the last 10 years, ranking the QB's against each other seems futile, the argument becomes who's line is worse,who had the worst receivers, etc., and for the most part they all had crap teams. I'll just rank them against their peers, personal best QB NFL rankings.
1 Bledsoe 2nd ranked QB in NFL 2002
2 Flutie 10th 1999
3 Losman 18th 2006
4 Johnson 24th 2000
5 Edwards 25th 2008
6 AVP 30th 2001
7 Fitz 32nd 2009
Thats depressing and except for Bledsoe and Flutie embarassing