The more I play with this lens, the more I love it.
Its sharp, no question. Sure it is theoretically a little less sharp than the 70-200 2.8 II at 70mm, good luck picking it. But you can also get in much closer, if I need 70mm, I will grab this lens due to better subject distance and weight.
Focus speed is faster than any lens I have used, even in low light its as quick as me pushing the shutter button. I put it out of focus, point at a subject, push the shutter release button and it focuses and shoots in one motion with out noticeable delay. Subjective test, sure... but that's how I use it, any lag from this lens isn't going to hinder me getting a shot.
I was shooting @ 1\50s last night, I don't like being this slow due to people motion blur, I would sooner up the ISO or put on the flash than risk the subject moving. So I just don't see IS being any help for me 99% of the time. But if it had IS I would be more content with the price.
Bokeh is good IMO
Plastic is good IMO
Flare handling is good IMO
If I had to come up with a complaint, it would be that I paid for IS but didn't get it! lol
I would love to see test shots side by side with the 24L 35L 50L @f/2.8