Julie, some believe "endurance" bikes are just marketing hype...and I have to believe it, too. You can have a "race" bike and flip or swap out the stem and it'd be the same as a more "endurance" marketed bike. It's more about geometry rather than type (as there's really not that much difference between a "race" and "endurance" bike). There are some "race" bikes that are built with a more relaxed geometry and some endurance bikes with a more "racey" geometry...you really have to look at each individual bike. Good luck with the purchase of your next bike.
"Limits are a state of mind: break them before they break you."
--Michael Cotty