Claris group works great from what I can tell, but I'm not all that savvy so anything to me is great.

From what I read the CAAD8 frame is one of the few entry level frames that is actually worth upgrading with better components, but I can understand someone's reservations with making any sort of investment on what is clearly an "entry level" bike. Either way, I am not expert, which is why I ask.

The Ultegra set was a mix of 6600 and 6700.