I just got the 70-200 f2.8 II IS and I can say that the IS does make a very noticeable difference on the tripod, especially if it's windy. There is far less micro jitters with the IS on. And used the with 2x extender, the jitters are even more noticeable without IS.
I haven't tested it extensively yet, but I did see a bit of the "Pan catching up my move late" issue with the IS on. But will have to test it more.
I haven't tested it extensively yet, but I did see a bit of the "Pan catching up my move late" issue with the IS on. But will have to test it more.