Maybe I misunderstood, but to even suggest the VC is better than the VR II is ridiculous.
I own both the Tamron 70-300 VC and the Nikon 70-200 VRII. From my personal experience, the Tamron VC is better than the Nikon 70-200. Maybe I got a bad VR unit on my Nikon, but I feel I have to be much more careful in my handheld technique to use anywhere near the slow shutter speeds I can use on my Tamron for similar focal lengths.
The Two lenses are really complimentary for me. When absolute IQ or fast aperture is needed, and I don't care about weight/bulk, the Nikon gets used (and used a lot, btw). But when I'm travelling, need a bit more reach, don't need the aperture, or simply don't want to haul around a big heavy lens, the 70-300 VC works wonders. Some of my best bird shots are with that lens. With the 70-200, I'm often wishing I had just a bit more reach.
As an aside, I originally had a Nikon 70-300 VR. I had that lens for over a year. It was a great lens, except that I was never satisfied with it's performance at 300mm, even at F/8. When the Tamron came out, I compared the two. The Tamron is very similar, but yielded better images at 300mm (not sharper images, but better contrast and "look", the kind of "better" that the Zeiss guys rave about with their lenses). I ended up keeping the Tamron.
Don't get me wrong, the Tamron has its issues too. Chief amongst them (for my copy) is a miscalibrated aperture, requiring me to dial in a bit of negative exposure when stopping down (to avoid overexposure). Also, at 300mm and minimum focus, the Tamron yielded more CA than my Nikon, although I didn't fully explore that (I didn't get the 70-300 for 300mm point-blank shooting!). But ultimately, the better stabilization and better 300mm IQ won it for me, and made for a good complement to my Nikon 70-200 VRII.