I want to upgrade to a 70-200 2.8. I have been lusting after the Nikon VRII but I have a little difficulty justifying the $2400. I am not a pro, but I do like to take great and sharp images. The lens will be used for many things but the emphasis will be on panning motorsports shots generally taken at 1/125 or faster and sometimes with flash. Lens reviews that I read mention 4 stops at like 1/40 which I won't really be using. Here is my question; should I get the more than half price sigma with no VR or the big bad VRII? Also, at those shutter speeds how important is VR? Thanks.