Why buy the 1007 over the 807?
First and foremost, the 1007 is a 9.2 Receiver whereas the 807 is only 7.2. Although the 807 can be configured to run height, wide, or surround back speakers, it only has 7 amps, which basically forces you to choose one of the three configurations. The 1007 is the least expensive Onkyo (and possibly all brands) receivers with 9 amps. That said, Onkyo' configuration limits you to either front or wide and surround backs.
The 1007 is also THX Ultra2 certified, the 807 is Select2.
In regards to build, they are very different. The 1007 is heavier in the front a la my 906 with the power supply in the middle front. the hcps is on the left side of the 807. this and other components make the 1007 more front heavy, whereas the 807 is more back heavy. They layout of the boards are completely different as well for the most part - this is visible through the top vents.
Pics comparing the two:Attachment 153582Attachment 153583Attachment 153584
The 1007 more closely matche the back panel of my 906/876 and the 807 shares the back panel with the previous 806. The position of the hdmi inputs is the easiest to tell.Why Buy the 3007 over the 1007?
Better Video processing via Reon HQV XV Chip
Front USB port and HDMI input
5 more watts per channel
One more video input (aux 2)Can the 1007 (or any Onkyo) output both wide and height simultaneously
No. Only receiver that can on the market at the moment appears to the Denon AVR4810. Please see earlier posts regarding setups possible.How does the upscaling compare?
Please see post #5Can I assign HDMI inputs to audio only inputs (ie Phono, CD)?
Yes - any unused HDMI input can be assigned to any input.Does the display overlay over 1080p 24fps?
Yes, you can see volume, audio track and bit rate and video resolution.