Hutz. If you want the latest codecs and feature set receivers are the way to go. I'm actually considering a receiver as a HT pre-pro to an amp for that reason. But make no mistake about it... fidelity is compromised more or less by inserting a large transformer that gives off large amounts of heat, a magnetic field and RF interference in the same box that processes low voltage, easily corrupted signals using adjacent dedicated boards, transistors and circuits.
The best receivers dedicate alot of design features to minimizing and insulating the electro-magnetic problems caused by proximity to the amp. Some do it better than others and its a matter of how much you want to compromise fidelity. The only way to completely eliminate these problems is to separate the amp from the processing.