i have owned an HK510 previously. Now a very happy Yamaha rxv2600. It's an audioholics product of the year.
and it DOES upconvert all incoming signals to 1080i via HDMI. (in fact, the ONLY receiver to date that does this, i think)

it also sounds great and is well built. i would not buy HK again. QC not up to par. imo.

thx