My wife has the full 105 alloy Synapse, and I can't say enough positive things about it. The new 105 feels nearly as sharp as my Dura-Ace 7800. The bike is fairly cheap ($1300), and just plain works. Not sure where you live, but if you're near an REI, you could buy it there, ride it for 2 weeks or 2 months or 2 years and then return it if you decide it's not right for you (lifetime unlimited return policy on everything from REI)