I heard/read watching reviews and such stuff that the very oldish version is faster for focusing a little than the version with motors but I think it depends a little on how strong the in body motor is as well which makes sense. Sharpness, well I watched an interesting video on youtube and it clearly showed the non VC much sharper, but the guy had VC switched on and did not even know how to properly use VC, so yeah he was using VC in daylight on a portrait type shot wide open so I imagine he had a high shutter speed all ready and all the VC did was blur his shots a little or he didn't even wait for it to settle? That's another thing I heard/read, with the VC version if you have it switched on you have to wait for about a second after focus before taking the shot, if not you will catch out the VC (as in it's not quite stable yet)