I had one before I got my current 60mm DefiLink setup.
It was definetly cool! It was nice having it display on the windshield, so you don't have to look down/over to see what's going on. The response of the number display is a tad slow, but the outer "analog" display is instantanious.
I never used the turbo timer feature, but it works the same way all the others do.
My BIGGEST gripe is that it displays in kg/cm, as opposed to PSI or BAR. Some people don't care, but I always hated having to do conversions in my head.
A very interesing product, none the less. If you need something compact, it's the way to go.