Seems the best advice.

Though I would build my own bike just because you'll end up changing the wheels, the seatpost, saddle, handlebar anyway. It's too bad bike industry overcharges ridiculously on framesets.

Great video! It is funny that I still talk to people who think carbon is too fragile or brittle, and so opt for another material.

As regards the OP question, I have had both the CAAD 10 and SS, and while I really liked both bikes, I much prefer the SS.

Waht do you mean by buzzing? I just noticed my frame make slight buzzing sounds while going over rough pavement, is that what you hear? Or is that an internal issue that should be looked at by an LBS?

I would personally get the CAAD 10 with 105. I don't know much about the higher end group sets but for about $1,600 or so the CAAD 10 is great for the money. I may get one next winter when they're on discount. Also look into a Scott CR1. Carbon and I think a better value than the SS

Racer's perspective here. The CAAD is a hell of a race bike for the money. Take the money you save and apply it to your license, race fees, and maybe race wheels. You can keep the stock wheels for training/pit wheels.

It mostly is cost. Racing can be expensive and most of the cost comes after you've bought your bike. You'll go through consumables like tires, chains, cassettes, etc. If you join a team, you'll have to buy a kit (or two). If you get serious about training, you might consider buying a power meter and hiring a coach. You'll have to drive to most races. These things add up.

And there is the significant chance of crashing.