revchuck 

Sara - I've been doing much the same figuring in my head, and have come to pretty much the same conclusions as you have.

I've already got two bikes I can use - a Specialized Allez and a Look 585 Optimum. Since in my case I'll have to travel to almost all my races, I'll be using one most of the time. It'll be the Allez, because it hurts me to think of dropping the Look, with its miles-deep clearcoat over carbon fiber, in a crit, and I can't really afford to replace it. Besides, the Allez is set up with mostly DA 7800, so it's not much of a sacrifice.

One thing we're doing differently is the cassette - I've ordered a 12-23 and will be using it in most (if not all) of my races. That might be worthwhile for you, though you probably have to do more climbing than I do. A disadvantage of the 12-23 is that the cheapest one you can get is Ultegra, while you can get a 12-25 in 105, which is about $25 or so cheaper.

I think that current aluminum frames ride well enough that you can delete the superior ride quality of carbon from consideration. My Allez is fine for 100 mile days, as is my CAAD9. IMO, tires, seat and wheels contribute more.

Unless you really want/need an entire bike, I'd seriously consider getting just a frameset and transferring everything from whichever bike you want to replace. You can save major bucks that way, especially if you find you need stuff other than what comes stock on the new bike.

Good luck on your quest!