CC makes good headsets. But I bought the frameset and it didn't include the headset, all that is in there was an upper and lower cup. Since I needed to buy one I decided to get a CK, and I wanted it red. So it wasn't anything against CC
The person you spoke to at Trek does not know what he is talking about. I owned a session carbon, and worked at a trek dealer too and I know for a fact the cups are removable. That is why the bike comes from the factory with a stock headset, and Trek also includes an angleset too. The only way to install the angleset is by removing the cups.