I have to agree with Stapfam (and it seems like I always do)... Plus a number of other posts are pushing towards a road bike...

But my hesitation is that you already have a CF road bike.

Aside from being old (which we all seem to be around here anyway!), What's wrong with it?
... Fit, Components, Ugly color?

If it's fit perhaps a good LBS could help (new seat, seat post, stem, bars, etc...)
If it's components, again a good LBS could bring it up to speed -- and probably give you a higher end bike at a lower cost than a new one).
If it's an ugly color -- just tell them it was donated by some homeless guy and you didn't want to hurt his feelings....