After getting over the initial set up problem, I have to say it sounds excellent, slightly warmer than the Denon.
The first thing I missed was the height option for the front stage, although the Yammy has a presence option, it's not as good as the Dolby version.
Also I thought it was less detailed, but after getting used to it, I think it is just less bright.
I then decided to bi-wire the front speakers and this made a huge difference, the detail has returned without being overly bright, the front sound stage is excellent.(not that it wasn't excellent with out the bi-wire, I just think my speakers suit being wired this way).
The Yammy sounds and feels much more powerfull than the Denon( and at the moment I am running it with out a sub), and remains tight and controlled at high volumes, the 1910 seemed to be strained in the centre channel at high volumes, voices where difficult to hear.
Also the Yammy is far better at steering the sound effects right to left etc. than the Denon. The DSP's are excellent when watching a particular type of films.
Alot of reviews say that the dialogue could be much better, but I have noticed no problems, but I do have a very good centre speaker.
It doesn't have a fancy blue light with "HD Audio" that comes on with a blu ray (if that's important to you) but you can ask it to display the decoder on the front panel so it still shows "Dolby True HD" for example.
The GUI, is a welcome step up from the Denon's, although it takes a while to get used too. Setup with the microphone is breeze, and much more accurate than the Denon's (I found with denon the results where different everytime) I have not had to change any of the speaker settings or levels after running the set up.
The Yammy does not have the Audessy Dynamic volume etc. I never used these so not a problem for me.
EDIT: Just found out that The Yamaha does has "Adaptive DRC" wihich is basically similar to the Dolby volume function, Although I still wont be using, but thought it was worth mentioning
The USB at the front is a welcome, my ipod pluged straight in and the remote control can be used to skip etc. and the album art / album / song title is shown on the TV screen, nice touch, as I was going to buy a dock, so I saved a few quid here.
In summary, it's a very worth while upgrade, great sounding and provides an excellent sound stage, partnered with the right kit I am sure anybody would be happy with it.