When I went to the store to buy a receiver the guy there said that the denons, marantz, onkyo, and harman kardons sound the best while sony, pioneer, kenwood and so on sounds average. Also, there is a huge price hike from the sonys etc to the higher end ones like onkyo etc. My question is, how exactly do these higher end receivers sound 'better'? Because quite frankly, I came from a friends house who had a 3 year old Dolby digital/dts sony receiver and it sounded unbelievable. A complete explanation would be nice becuase I'm likely to base my buying decision on you guys.