I need to buy my first pair of road shoes (to go with my new bike - a 2004 Cervelo One!), but I'm not sure where to start. I've heard that tri-specific shoes make a difference in transition, but most bike shops I've visited don't seem to carry a wide selection of them if they carry any at all. I've also read a little on these pages about carbon vs. not carbon, etc... So I'm wondering how much of a difference tri-specific shoes make, and what sort of features I should be looking for. Does anyone have any suggestions for some good but inexpensive shoes?