I can't decide, both seem to fit my needs. I just need someone with experience to push me this way or that. I haven't heard the 520, but I have heard other models and they sounded good to me. Please help, what are the important difference's that can be found? What I found is that the 520 doesn't have DTS ES or B speaker outs; the Yamaha doesn't have logic 7 and an additional remote.