The Felt. I have a new CAAD8 myself and whilst I love it (to look at mostly as haven't had much chance to get out on it yet) , the Felt is just such a bargain at this price with the Tiagra groupset. It's 10 speed too which should make the climbs a little easier and 25c tyres which should be a bit more comfortable.
The only caveat I suppose is the CAAD8 frame is the same as all the others in the range and by all accounts is one of the best alu frames on the market. But the Felt looks a massive bargain!