I own the sex and honestly it is fantastic. If you get the C4S upgrade it will be even better and with the impedence switches it is even more convinient. It also drives everything from low impedence to high impedence phones wonderfully. Also the best part is I can't tube roll it. I know it sounds strange but if I don't have a choice I can't spend money. On the other hand finding a matched pair is a pain in the butt. But overall I love my sex. It sounds fantastic with my LCD2's.
I know what you mean. I thought I'd be bummed about that, but it's kind of nice to know that it's already as good as it gets (which is darn good).