Run for a few months now. Noticed something just now as I replied to a PM. My peak boost is exactly (or damn close to exactly) where it was before the weather got drasticly colder. And here the weather changed from mildly uncomfortably warm, to very uncomfortably cold in one afternoon. If I were still running the AVCR or the ProfecB I'd still be wrestling the boost under control.
Peaks on maps that were 19 are still 19, 21 still 21. The plateaus are still smooth and no longer or shorter than when it was hot out. I'm very pleased.
As far as cost, I walked into a local dealer and gave them $14 and change for the unit. They didn't have the harness, which I'd like, but I made my own without any issues.
edit: I also have raised my gain (55 from...47 I think was the previous solid setting) and am happy with the occasional .5 psi spike which rarely touches the 100% column I've prepared for that event. I run the 10 ohm resistor, and I installed a diode across the leads (band to + side) to protect the UTEC a bit more. Not sure if either is needed of course, just added precautions. And, yeah, the solenoid has no polarity as far as I've encountered.