I just set up my Coolscan IV ED and , so far at least, I am ecstatic! I scanned some slides I had previously scanned with my old H-P ( Model 1 not the S20) using Vuescan on the H-P. The IV ED was much faster and gave bigger files right off the bat( about 35 megs for each slide depending on the nature of the scan)and the quality was much, much better. I have not done any film strips yet, but I am eager to start. Generally, I shoot Supra 100 negative film when I shoot for prints, although the bulk of what I do is slides.
I got my IV ED here in Atlanta at Showcase Photo, a large dealer that caters to the professional market. They have a couple of 4000's in stock and several IV's too. I was the first kid on my block with the IV . Write me off line if you would like Showcase's phone and my contact there. My address is in my profile, I think.
By the way, the 4000 ED is quite a pro machine and is designed to run off the "firewire" port on a very " strong" computer. I would not even consider it unless I had at least 500-1000 mhz processor and a min. of 256 ram, plus a monster hard drive.