No, test the bikes out and go for what you find most comfortable.
Especially with road bikes, shops may too quickly put you on a small frame with low handlebars optimized for weekend rides and races, but maybe not comfortable for commuting/daily use.
Agree with this. Your riding style can affect the frame size you want. By these people,
http://www.competitivecyclist.com/ht...ad_riding.html there are three styles of fit. Most shops by default seem to use the competitive fit. That is what the LBS I bought my bike from fit me with and I was never able to get comfortable on the bike. A year and a half late I replaced the bike with one of the same model a full size larger and it rides so much more comfortably.