I just got STR-DG810 yesterday. I bought it as an upgrade from an old 5.1 receiver by Aiwa. Once I got a hang of a remote, the set up was really easy and menus pretty intuitive even without onscreen display. I used the included microphone for speakers setup.
I decided to only use HDMI connections for my system. I connected Comast HD/DVR box (outputs at 1080i max) and Samsung HD-960 upconverting DVD player with HDMI output of up to 1080p. Then HDMI cable to my Smsung DLP 1080p display. HD programming with DD5.1 from Comcast box programming was automatically recognized by the receiver. Trouble came playing DVDs with DD5.1 that kept only showing up as 2 channel audio. On receiver's display it would show up as PCM 48 and only 2 speaker symbols would show up. DTS encoded DVDs would not have any sound at all. Finally I figured out that that was the factory setting on DVD player. I had to enable DTS and switch output to PCM over HDMI. Tricky, so if you have that DVD player make sure to go into audio settings. DVDs looked great upconverted to 1080p and sound is amazing. For me it was a huge upgrade in sound/video. I could really recommend this receiver you could get a great deal on Amazon. After 2 days of using it, the thing that I would improve would be adding a multicolor display because it only shows text/symbols in white, so everything tends to look too blurry from 6-10 feet away. If you could live with that, go for it. I would be happy to answer questions related to my setup.