First what's wrong with your current bike? Why do you want a new bike? Nobody can really give you advice about a bike until you tell us what you're looking for.

Here's my .02.

There's two things to look for in a bike - frame and components.

The only thing that matters about the frame is the fit and handling. Material choice is so overrated. Yes metal will last longer than carbon fiber. But you may grow tired of the bike before it is even an issue. Things like speed and road dampening can be changed with tire selection. So buy a frame that fits and don't worry about anything else.

In the price range you're looking at Shimano is really your only choice for components. 105, Ultegra and Dura Ace are the three levels. Dura Ace is too expensive and less reliable because it's built to be lightweight for racers. Lance does not ride the same bike year after year. Ultegra is a little smoother, but 105 is fine.

Kudos to you for being skeptical about what the bike saleman has to say about his product and that of his competition.

Have fun shopping!

Veronica