Yamaha vs Denon/Marantz sound differences would largely be the dsp involved (Yamaha with it's YPAO room correction, parametric eq and various dsp sound modes) vs the Audyssey room correction Denon/Marantz use, the graphic eq, and the various dsp/sound modes). In pure direct mode they should be indistinguishable. I have no experience owning Yamaha, but have a couple Denons, an Onkyo and a Sony now and have used Pioneer as well. As with many avrs the most powerful amp sections tend to reside in their flagship and other upper-end models. What speakers and speaker layout do you have?