CAAD10 vs. Specialized Amira Comp

[lsc]

Hello. First post, long time lurker here.
I was hoping to get some opinions on what's the better bike to buy.

Basically I have a rough budget of $2000. For the time being the bike would mainly be used for morning "training"/fitness/casual group rides but one day I'd like to race. I've been riding an old steel frame that weighs as much as drain pipe equipped with 600 and I just desperately want something modern that's better than me to motivate me to ride more (and that will make me go faster up hills). Currently most of my road rides are around 30mi and I like to include some hills, plus I commute on a fixed gear, but if time allows and when I have a roadie I like I'd be getting out on much longer rides on the weekend.

For $AU2000 I can get a demo 2011 Specialized Amira Comp - carbon frame, full Shimano 105, Fulcrum Racing 6 wheelset (research has led me to believe that means a 5 hub paired with a 7 rim).
http://www.specialized.com/au/gb/bc/...01&scname=Road

For $2200 RRP, hopefully less if I shop around (cheapest I've seen advertised is $1800 in another state), I can get a Cannondale CAAD10 - alloy frame, 105 except for the FSA Gossamer Pro BB30 cranks and Tektro R580 brakes, Shimano RS10 wheelset.
http://www.cannondale.com/aus/2011/b...0-womens-5-105

I'm not super fussed about the 105 components as they are more easily replaced/upgraded, and I imagine it would be better than my ancient 600 Ultegra. I have Rival on my cross bike and I don't love it enough to want to fork out the extra for the Rival CAAD10 - having said that if I could get it on special for the same price as the 105 version I'd pick it. The first thing I'd upgrade on either bike is the wheelset.

I know I should probably test ride the CAAD10 but it's really hard finding places to test ride bikes in my size. I've ridden at 48cm 2010 Amira Expert and that felt pretty good (regret not buying that one), and the Cannondale 44cm geo looks similar.

So I guess the question is about the frame... Entry-level carbon vs. top alloy? What would you get? And to throw something else in the equation, is the Supersix worth the extra grand over the CAAD10?

Thank you for your opinion in advance, ladies.