Onkyo's rated power is much lower than what is stated. Even though it is specified that the Onkyo is 100W with all channels running it mostlikely is running about 70W. I find this for all Onkyo or Onkyo Integra models. The Denon, Yamaha, NAD and Rotel actually run in the range they state. So if they say they are 100W per channel then it is 100W per channel or close to it. Try Rotel RSX1055, NAD 762.
If you plan to spend as much on the M80... give a listen to Monitor Audio Silver S8, Paradigm Reference 100, PMC TB2, Quad 22L, Warfedale Pacific Evolution Evo 400
