She is 5'6" with a sort of long 31" inseam. We knew the previous Madones fit her perfectly in a 51 WSD. However, for '08, Trek changed the sizes and geometry. They went to a 50 and 52 and both bikes have more rise then the previous Madone. The top tube of the 50 looks like a better fit, but the 50 would require a "tall" seat post cap, see here:



So we decided on the 52, although she may need to shorten the stem a hair. The bikes generally are very close, I think the tall cap is fine, but like bikes with a more or less neutral fit.

I don't know about R&D at Specialized, but would have my doubts that they put more effort in that Trek. Specialized is a importer and specs bikes to be built. I'm sure they do R&D, but are still constrained by the manufacturer building their bikes.

Trek designs and build their own high end bikes. And just looking at the major innovations in the '08 Madone would prove this out. New head tube and bearing design, massive bottom bracket, and new seat mast design. All together make it lighter with excellent handling.

As for riding an '08, there are some out there. We found one in Columbus, Ohio (about 2 hours away), so took an afternoon to go over and ride. This confirmed the size and ride. Although, I'm not real pleased a Trek Superstore in Columbus has one on the floor, and Trek still can't deliver one to our local dealer.

All that said, too many variables, so go with fit first and the rest will fall into place.

P.S. Nothing wrong with Specialized, just take everything you hear with a grain of salt, also our 5 year wants a Specialized Allez jr, very bad...