Cannondale CAAD9-5 is also another bike you may want to look at. Felt, Giant, Raleigh also makes bikes in that price range...

Really going by feel is the best way. Most bikes if they come with the same components aren't going to be much different from the other. Only difference is the frame.

Many recommend the CAAD9 because it's a stiff aluminum frame... and the new one comes with the BB30 bottom bracket.