Wow...first I've seen of this thread. Guess I need to get out more.
FWIW I was unable to make a gtg and get an RC tune earlier this year, but I was taking the Jetta to VIR for a track weekend and needed a tune. Was hanging out at a local shop and saw the Kerma sticker on the door, so I dropped the $400 and boosted up.
This was my first *formal* track event, but I was able to hang with or pass everyone else in my group except a couple of the M3s. This was a BMWCCA event, so my class was mostly 325s, 330s, some Mini's, and E36 M3s. I laid down a smoke cloud doing it, but running WFO most of the time I expected it. I was tickled with my performance, on touring tires as well!
On the drive out and back I did notice that my fuel economy was down roughly 10% from "pre-tune", and got in touch with Charlie. I got one of the standard "eff off" type e-mails that were apparently typical for those couple weeks in July.
He did eventually get back to me and we chatted (I think he was checking to see if I was an idiot and/or if there was any data backing up my claim), and after I explained some of the technical observations he had some ideas on how to tweak it to keep both the power and economy.
I'm only on my 2nd tank since the newest tune, but with less than a quarter tank remaining the total miles for the tank is projecting ~670, which is 10% higher than it had been running for the same driving conditions. It's idling rougher than it was, but I'm not so concerned with that. Perhaps if he gets ahead of the curve at Kerma we can keep tweaking.
I've never seen a company that makes a perfect product, and it's how a company deals with mistakes that defines them...if that makes any sense. I was pretty pissed when I got my first e-mail back telling me to pound sand, but Charlie has since made up for it, so for now I'll keep the faith.
Cheers-
Aaron