So I'm on the verge of buying a fairly expensive (for me) racing bike...both bikes are tiagra/105 and both are pretty much untestable because they're online store bikes.

I'm unsure about the Schwinn frame (as previously posted) being the right size for me, it is a large frame and we compared the measurements of the large to my '05 Langster, and it seemed to be a good match, if not the same size. I know pretty much that the '05 Allez will be not much different from the '05 Langster frame as they're both from the same stable and of the same material. The Allez is the same size as my Langster.

On material, I'm concerned about the carbon seat stays on the Schwinn. The '05 Allez is all aluminum, apart from the forks. My Dad's an old school cyclist and doesn't trust carbon at all; he's saying that the bike won't last. Obviously, as the bike is an "entry level" model it's not something I have a lot of confidence in. Does anyone have experience with these seat stays on bikes that cost around 830 ($1,000)- I'm more than likely not going to be racing the bike (although that may change) and would like to do some endurance riding/just for fun kind of thing.

Price wise, the Allez Sport is 499 and the Fastback Comp is 535. These are both reduced bikes we're talking about.

Any help would be appreciated here, just looking for as many opinions as I can before I take the plunge...eeek.