The yamaha and Denon have traditionally had a very different overall sound. I would ask "if you liked the sound of your denon in your setup, or not?" If it sounded great with your existing speakers/setup, I would stay with Denon likely.
The Yamaha's traditionally were a bit leaner in the bass, not so warm sounding, a bit more analytical (at least at the lower price points), a little hollower in the mid-range, compared to the Denon (which was warmer, more full-bodied, slightly rolled off in the high's, with fatter bass). So, I would say depends on the rest of your system, definitely.
Another receiver to consider is Harmon Kardon in that price, with lots of power, refined sound, and latest processing. Although the Denon's excellent Audyssey is hard to beat.
Good luck
