That is a dead heat IMO. Probably why you are not getting a lot of feedback. Both will be fantastic, the Denon street price is about $500 more than the Yamaha. I think the Yamaha might have a little better Upscaling potential, and the Denon has a little better onscreen interface.
If you can get the Denon $100 cheaper with warranty, and without any damage to it, that would be the end of the decision for me. You are not going to be able to tell any difference in video switching between these two models.