Floyd Mayweather's weaknesses?

At the time, I thought Williams was the worst matchup for Floyd and would win a decision by outworking him. But now I think Floyd would have won, in a dull fight. Williams was so bad defensively, didn't use his height and range, didn't have much ring smarts.

Floyd would lower Williams's punch output, and it would make it boring/ugly in doing so, but I think his ring smarts, skills, and just plain superiority as a fighter would overcome the physical advantages and workrate of Williams.