Biggest size advantage at a non-Heavyweight weight class?

[donnydarkoIRL]

I was a huge Tommy Hearns fan, but I sometimes thought it was a bit unfair watching him come in at 147 with that huge height and reach advantage. Most shorter fighters had absolutely no chance against him. Although the weight draining did take it's effect on some fights, most notably the first Leonard fight (one of my favs of all time), when Leonard fought through some heavy eye damage and began cracking those skinny ribs and finally pounding Hearns into submission in the 14th round.

He had almost 5 inches of height on Hagler.
I think height can be a disadvantage if fighters know how to handle it.