The IRD freewheels are quite nice. Well, nice looking, I bought one, but haven't used it yet, so I don't know how it works. I'm waiting for the El cheapo new production Shimano one on my daily rider to wear out or disgust me w/its poor performance, neither of which has happened yet. Seems to work fine. My only gripe is the black large cog and the color, so I don't know if I would put it on a bike where looks were super important.

FWIW, the shimano freewheel has been submitted to fairly hard use, having to haul me (180 lbs) and my kid in a trailer around. Shifts fine, I have it mated with a Dura Ace RD-7700-GS rear derailleur and a pretty nice SRAM chain, one of their better ones. My only complaint is that they look department store - they seem to work fine in my experience (this isn't the first one I've used).

For comparison purposes, the cheapo Shimano replaced a Dura Ace MF7400 rear, the only difference I noted was they sounded a little different when freewheeling, couldn't tell any significant shifting difference.