My Coolscan IV is about two weeks old. I have been switching between Nikon
Scan 3.0 used as a TWAIN import for Photoshop 6 and Vuescan (7.0.10 to
date). Nikon Scan 3.0 has worked without the crashes that some have
complained of. Nikon Scan wors flawlessly on my system - my OS is Win 98SE.
So far the Coolscan IV has been very satisfying.
Vuescan has not performed any better that Nikon Scan 3.0. Nikon Scan seems
to scan color negatives better than Vuescan. The analog gain in Nikon Scan
is better that using Vuescan multi passes for dark slides. That is all for
my observations to date.