I understand the question and my answer may be from what I read on this site and other sites as well. I, personally, have no track experience, but manufacturers like Speedtech, DSE and Ridetech are from guys with real world experience. There are lots of guys here who swear by the aforementioned brands and if I was in the market I wouldn't have an issue buying either one. Now, as far as who's the best of those 3...it probably remains to be a personal choice. As all three of these from what I hear and have read are top brands and they all put alot of research into their products. Me personally, I don't like the way Heidt's and BMI stuff looks. That's just me though...so anyone who has it, don't shoot me.
I think Heidt's caters more to the hot rod crown and not much to the pro-tourer. To me, Heidt's need to come up with more newer stuff. They've been selling the same stuff from 10 years ago. Some of thier suspension stuff hasn't come into the age of bigger, wider wheels.