What doesn't Sigma 24-70mm f2.8 offer?

You are quite right of course and I'm not settled on what I would I get yet anyway. Let's hope the Siggy works out. It fits in my bag just right anyway .

If I could find a Sigma at £199.99 i'd snap it up in a heartbeat. Looked in my local Jessops and it was £299.99.

I did have to send mine back for calibration, as it was having focusing issues. I got it back in about 11 business days and now it performs great.

"I just bought my first L !" --I know it's a often misunderstood statement, but it means a lot to some people here.

Not quite sure why. At the level that most of us hobbyists are shooting at I can't see a difference. Sure, wide open at a lenses maximun zoom and at 100% crop the difference may be slight difference. The Canon L may have better color, but how many on this forum print the shots withough adjusting the colors in PS anyway? Once you get away from the super-cheap lenses and into the 'moderate' price range (where I consider the Sigma EX and better Tamron lenses to be) differences will be slight and people will have their favorites.