I'm no expert in the challenging setting you are shooting in, this post just caught my eye and made for some very interesting reading.
I'll go ahead suggest if you need a sharp longer constant f/2.8 zoom that you consider the Sigma 70-200mm f/2.8 EX OS HSM (the newest non macro version). The reviews of it are good, and there are lot of fans of it here in the Third Party lens forum. It goes for around $1250 today, and is a great performing lens that rivals the sharpness and color rendition of some of the older competing Nikkors. I have a much earlier version of the non-OS Sigma 70-20mm f/2.8 and have been very happy with it. But by all reports the newest version is even better then my 7 year old sample.
Do a little research there's some good info and reviews out there on it, see what you think.