I bought my 70-200/4L IS USM a few weeks ago.
And i have to say. This might be one of the (if not the
one) coolest piece of gadgets i ever bought.
The brillianse and buildquality is superb and it feels very solid.
The switch for autofocus-distance is very good, and makes the autofocus very very quick. I mainly shoot motorcycles outdoors, and this lens have no problem what so ever to quickly focus on a moving fast target.
I also like the feature to change between panorama-IS and full-IS
I have had a few issues with it not finding the focus spot on, but i think it's me and not the equipment.
I've also noticed that you gain much if you shoot in RAW and pull the RAW-sharpness up a tad when editing, or if you go into the camera menu and push the sharpness up a few steps.
Not sure if thats what folks have to do, but i do it anyway.
A few samples: