Picking a receiver is more a function of picking features. IOW, from a sound quality soundpoint, you'll not likely hear a dramatic difference, if any at all. Therefore, I'd suggest going through their feature list and pick which one best serves your needs. To me, everything else considered equal, I'd look at the DAC's, video upconversion/switching (if for HT), auto room eq, and Pure Direct. I could care less about DSP's, but that's me. Both the companies you've chosen have very good reputations, although I think Yammie has a bit better reliability record.

Hope this helps.