Fitz is playing well under very tough circumstances. I think he is clearly a guy who can "drive the Cadillac" as Bill Parcells used to say about Drew Bledsoe in his prime. He's not Brett Favre or Peyton Manning, but you can win games with him at QB if you put quality players around him. The question is, can you win a championship without a HOF QB? Some teams have done it, but most champions have had elite QBs. So the real question, IMO, is whether the Bills think they need a HOF caliber QB to win a championship. If so, then they really should take one next season with their top overall pick. If not, then they will get better much faster by drafting at other positions.
PS- Fitz stays on the team regardless.