Of the two seperate times that I used mine, it worked great. I've postponed any more testing until after I've upgrade my saggy 137k stock suspension. Should have some better times and track-comparisons after the holidays.
Mine work (both of them.) The discussion on the V8SHO list concluded that they are fairly accurate, too. They overstate the trap speed compared to what the 1/4mile tracks use, but only by a couple mph. It's been s***ty conditions out there for a while, so I haven't had any new times to post. Every time I get out of the city, it's raining, snowing, icy, too much traffic, etc.
Well, you've already heard my words, but seeing as how it has been 9 months+, here they are again.
For $44, it's a good bargain. The new unit has LOTS more features, but for the money, the old unit is very good. I don't use it much b/c I live in the city and I don't have any convenient 1/4 mile flat stretches to benchmark my performance every week or so like I'd like to. However, once in a while I get out in the countryside and let 'er rip, and it's nice to see proof in numbers that I'm not losing power to the ground through a slipping TC or other mechanical problems.
And the G-tech at least gives you SOME recourse to the haters who claim your "butt dyno" exaggerates your cars performance.