It looks like Gregg's has some fitters who are trained by Serotta. Here's a link that explains the different levels of training that Serotta offers their fitters and the Serotta fit philosopy. http://www.serotta.com/pages/calendar.html#fun
http://www.serotta.com/SICI.html

I've worked with 3 different Serotta fitters and have been very pleased with the results.

Serotta has a protype bicycle that is adjustable. The fitter can set it up to your specs. so you can try out the position. Then adjustments can be made according to what is comfortable for you.

You also get a written form with all of your bike specs on it. Very helpful if anything gets changed. Unfortunately, not all bike shop personel understand what the numbers mean.

I went to a Serotta fitter in Cincy to have my bike refitted and I had all the numbers on it. When I was looking for my custom frame and wanted to demo bikes I went to a shop in Boulder and they were able to take the numbers off the old bike and use them to set up the demo bikes. One bike I demoed was too big for me but it was set up so well that I could have sworn it fit.

When I bought my custom frame the shop insisted on doing their own fitting, just to be sure they had the specs right. Unlike others who have built custom bikes I've not had to change a thing on my setup.

Also, keep in mind that even though the Serotta fit system is wonderful, the fitting is only as good as the person who is doing it.