Searching for a longer, fastish zoom to companion with my Leica 14-50, and the early non-OS version of this lens definitely SEEMS to hit all the check boxes - non-extending, parafocal, no support needed, etc... main complaints seem to be autofocus related, which wouldn't work anyway. I cannot find this lens available for rental to evaluate myself.

Has anybody used it, have a report, or video samples? Thanks

I have the Tokina 50-135/2.8 and am very happy with it.
Very sharp and parfocal. Very nice build and feel.
I've got a Nikon so I can comment on the gh2 part.

I wound up finding an inexpensive used Sigma 50-150 via eBay, and paired it with one of the Fotodiox Nikon G adapters.

The adapter is a wee bit bleh... fit is fine, but the slot for the aperture dial lever wasn't clocked correctly, and the detents were set in strange places, so there would be hard clicks right before and after the limits of full aperture throw and it was impossible to open the aperture fully. Three minutes with some screwdrivers and a dremel solved that issue, and the adapter is now working splendidly at a couple hundred less than a MFT/Novoflex/etc version.

The lens... Holy Crap. This is exactly what I was hoping it would be. Sharp enough, good rendering, light enough (no support necessary), shmooooove focus and zoom, parfocal, repeatable, and constant. Auto nothing, but it'll convey nicely if I ever rent or buy S35.