I have used the cheaper version (80-200mm f/2.8D AF ED-IF ) for a year now. First with an N60, N70, and now the N80.
The only time I can remember the autofocus not being fast enough was when "machine-gunning" a concorde take-off... about 3 of the 10 shots came out blurry
But other than that... I love it, and think it's great. So I'd go with the lsss costing model. (unless you get to shoot concordes every day)