Really confused here guys.

Trying to decide between the 24-105mm F4L and 100mm f2.8L IS USM? I know they're two very different lenses, but to be honest the 24-105mm ribbon issue thread I saw recently has put me off. Up until then, I had only heard praise for this lens.

Saw some shots of the 100mm macro, which looked extremely sharp. I read some reviews of both, and both seem great.

Anyone have some regular usage shots of the 100mm macro? I know they're not going to substitute for each other on all purposes, but I am wanting to spend my money on the most solidly performing lens.

So, how sharp are the shots on these lenses? If it helps, I am replacing my 24-135mm IS USM.

Thanks!