I got ahold of the guy from SoCal I bought the car from almost 3 years ago--he'd forgotten it was in there (wasn't listed as a "feature" on the car) and was pretty excited when I brought it to his attention. He's pretty sure it was an IRS unit and "held it's adjustment forever". That was certainly my experience.

I'll have to contact Dave and see if he has another one laying around...

Oh, and re: the better finish on the IRS hubs, I'd bet that's as much a matter of the level of finish Frank's willing to pay for/mark up. The retail price is (iir) pretty similar, but IRS is selling them to Frank who has to mark 'em up where IRS maybe does a bit more polish/finishing before marking 'em up to retail. The Carpet Knife 3.2R and earlier had that big round left side hub too while the IRS (and L4 and...) had the nice machined down hub.

And OD is right...REALLY hard to beat the Niftech setup. But cha gotta pay to play...