Do you prefer to use IS on your EF-mount lenses? I know some say it's critical for video and others say it's awful... over-compensates and locks on and is jerky. I'm on the fence, some lenses seem ok, others not so much. The Tamron lenses, for instance have great IS for stills but not video. Undecided on whether or not I should upgrade from the 70-200mm f2.8 L to the 70-200mm f2.8 L IS II. Hmm.. Ok with the IS on the 17-55mm f2.8 IS so far, but it does have fall off on larger than 1.6X sensors.