I'm 5' 6-1/2" with short legs. With a 90mm +6 degree stem the cockpit length of the 17" Trek 520 would come in just a few mm shorter than my cross bike with a 0 degree stem and my race bike with a -6 degree stem. I love the fit of both of these bikes. Personally, if I were buying today I'd choose the 17" with a 90mm stem over the 19" with an 80mm stem. I think the nominally quicker handling would suit my riding style a little better.