I honestly think that of those 4, 3 of them would have been mediocre on the bills regardless.
Big Ben got put in a perfect situation, and Eli caught lightning in a bottle. I'm don't think Eli is a top 10 starting QB.
Drafting some O-linemen was a start, but there's still huge holes to fill there, which means we're not going to be that effective on offense (for the 5th year in a row?)