I think you will hear absolutely no difference whatsover between the XPA-2, XPA-5, Rotel, Carver, or any other good amps, except for the gain volume since different amps will have different gain voltage. Volume matching is critical when comparing components.
The one thing to look for in any amp or preamp is the build quality. Emotiva amps have TOP NOTCH EXCELLENT build quality. They are built like a tank. And they weigh like a tank. They are built for excellent sound quality and built to last.
My Emotiva MPS-2 amp is way too heavy!
Actually, I wish my amp were only 75 pounds, instead of 118 pounds!
My only complaint about Emotiva is that they are too heavy and too bulky!