Well I got a call from my local dealer yesterday, my 24-105L IS was waiting for me! I jumped in my car to go take a look. I told myself on the drive down, I would look/test then MAYBE... buy. I have been agonising over this lens and the 24-70L 2.8. Which I demo'd for all of last week. I tested 24-105L store lens, which was about 2 hours old, while the salesman went to get mine from the back, all I can say is WOW! I happened to have my 20D with me, bonus, when he returned he had brought a big box of them. They where still on the shipping dock in receiving. He kindly let me try 4 brand new lenses and let me use the store computer to do some pix peeping, it appears Canon has got their act together with the QC on this lens. All 5 lenses were the same! I mean we really could not find any difference between them. We tried all different apertures, f4-f22 @ 24mm, 50mm 105mm with my camera on a tripod. I used my remote with the mirror lockup function ON. No mirror slap, and no hand movement, the IS OFF. The results from this lens have blown me away. I wanted to test it against the store 24-70L but after close to 2 hours of swapping lenses and uploading to the store computer I though I wouldn't push my luck with this guy. So I bought it! The store has a 15 day no questions asked return policy. This lens has completed, well for now, my setup. I have the 10-22mm EFS, now this 24-105L, and a 75-300 IS. I had a 17-40L also an f4, 2 weeks ago, another great lens, but it didn't have enough reach for me. Very sharp lens, but IMO this one beats it hands down, and the IS is a big bonus for me! I took some quick shots of a new Porches in a near by parking stall with the IS on, hand held, started @ f4 and stopped it down to f22 with individual shots. Looking at the pictures on my computer, I am VERY VERY satisfied. I really suggest you try this lens if you are thinking about getting the 24-70L 2.8, while it is a different creature, for me, the 24-105L is the way to go. It balances great on my 20D, the 70mm just a little too much for me. Build quality is excellent for both, I mean they are Lís. Itís pricy but I am one happy camper! I will follow up in a few days of real world shooting. TRY IT! YOU'LL LIKE IT!