Anyone with experience of the Tamron 24-70mm f/2.8 Di VC USD?

I am interested in any comments by those who have used this lens in any manner.
I am a particularly interested in comments regarding the use of the Tamron 24-70mm f/2.8 Di VC USD when shooting video.
Experiences with the lens, handheld, on a 5DmkII or 5DMkIII would be wonderful.
Comments specifically regarding ZOOMING, whilst videoing, handheld: and the effect of the VC would be exceptionally useful.

Thank you,

WW