Canon EF-S 17-55 f/2.8 IS USM vs EF 24-70/2.8L

I've got the 24-70 2.8L and am not completely happy with the picture sharpness at 2.8. I can see a noticable softness that goes away at 4.0. Because I shoot weddings, the 2.8 was a primary reason for buying the lens. My question is, does anyone have the same problem? Is this something I can get readjusted by Canon, or should I consider selling the lens and getting the Canon EF-S 17-55 f/2.8 IS USM? Does the 17-55 perform better at 2.8? My camera is a 30D.

I too would like to hear more on this cause when the Tamron 28-75 f/2.8 came out owners of both lens were claiming the Tamron preformed better wide open but I don't know if thats still the case or not ...

i got that softness as well on f2.8, but if i can use faster shutter speed with good enough light then i can get little shorp pics, but don't forget that adding sharpness from photoshop or so will result Amazing pics.
Don't worry, 24-70L considered as one of the best canon lenses.

There is a comparison from the-digital-picture web site:

http://www.the-digital-picture.com …8-IS-USM-Lens-Review.aspx

"At all overlapping focal lengths and apertures, the 17-55 is sharper than my Canon EF 24-70mm f/2.8 L USM Lens."