What are your thoughts on Aluminum vs. Steel frames?
Aluminum all the way.
The frames are stiffer, lighter, and more modern. Some people say that aluminum has a harsh ride. I have been riding my Cannondale R700 (has an aluminum frame) for about three months now, and i have no complaints.
Definitely aluminum. Although I can't deny that full-carbon feels amazing, if it's a toss-up between the two, go with aluminum. I did, still don't regret it, still love the bike (QR Kilo) although I've now had the opportunity to go beyond it, still ride races on it and still think it's great.