Denon 890 VS 790

I am on a fence as to which of these two to get. I have a B&K 307 which is having problems with my new Direct TV HD DVR HR22-100. The sound issues that plague the older recievers. Figure to get a new HDMI reciever to get all the new sound codecs Dolby TrueHD etc plus Audyssey souinds interesting. Just wondering is it worth $200 for 15 more watts, a better Anchor Bay Technologies chip, and a somewhat better GUI interface. Also would there be a sound improvement going from 6 year old technology the B&K sound really great just do not want to get a newer reciever to find out my older one sounds better. The software upgrade to fix the sound issue witht he DVR would cost as much as the 890 plus I would have to ship it and such. One last thing is the upverting on the Denon so good that I should let it do all the upverting rather than my Sony 2020, the HR22-100 and the PS3. Thanks for any info.