i wouldn't put too much time into his responses, almost every DAC thread has his name on it mentioning the same LINN DAC's as significantly better than any other. I think he's vested somehow...either dealer, importer, or employee.
Either way it doesn't really matter and detracts from the thread of comparing the qb9 to the c7xe.
I have not heard the c7xe but have had the qb9 in my system at one point. I'm definitiely partial to computer based front ends now so on connection options only i would choose the qb9 over the c7xe. I believe shy of the dx5 though the qb9 should employ the best Ayre has in their lineup.