I never heard a bad thing about TMS chip tuning, they are dyno tuned by Jim Conforti, his specialty is BMW tuning and he has been doing this since most tuners wore diapers. Most of his chips put out more than the rated hp-tq figures (check out Euro Tuners project on the E30-325) This was the first mod I did to my car, and I still remember the smile on my face during the first drive. It actually felt like bigger motor. If you like the MarkD, then go with it, I just wanted to let the club know that the TMS's were on sale