I personally like the warm sound of the Denons, the Yamaha's sound bright to me.
Is it purely for movies or movies / music use. Denons tend to have a better reputation when it comes to music modes also.
Also if I was to go Yamaha, I would get one from Germany (I visit there once/twice a month) you can get them mail order for circa £660, same pan-euro warranty as the UK sold ones.
I always say listen to you ears, but it's near impossible with a new product.
Best of luck in your choice.
Regards,
Chris