You need to decide whether you're set on carbon. If you are, you need to think why you want carbon. I used to be under the impression that carbon was for saving weight, but found out that that's not really the case . For example, my CAAD10 4 weighs less than a $3000+ carbon Focus I saw in an LBS. It was explained to me that people get carbon to get a gentler ride as it absorbs the impact more. Because of this though, if you don't get a very good carbon frame, your purchase of carbon will be in vain and the money wasted. Since I'm young and in shape, I don't really care if I get some extra stiffness in my bike and I really love my aluminum CAAD10. No complaints about vibrations. There is also the impact factor of carbon frames - they can crack from simply falling over. So once you decide on the material, your purchase will be much easier.