I too would put Kenny above Bisping for that reason. Plus Kenny was a finisher. Tough to be that good at finishing at 155. That said, Kenny doesn't really have 1 career defining win. His best win of his career may be Guida or Joe Daddy. Not that Bisping has many if any career defining wins.
Yeah Kenny got the fast track due to his likeable personality, memorable fights and being TUF alum. He also got the benefit of fighting before the divisions really started to develop. I don't think even the best Kenny Florian would be a current top 5 LW or FW. He also lost all his biggest fights. 0-3 in title fights and lost TUF Finale. Bisping atleast has the title of TUF winner. Even if his Finale opponent was the worst in TUF history.