I found SD signal on my Panasonic TV is not accurately displayed. When I choose 4:3 aspect on TV, the graphic is displayed in exactly 4:3 ratio. However there is actually 16 pixels horizontal overscan area for SD signal, as a result the graphic is centrally squeezed and I could easily tell from those not so round button indicators when I'm doing my (not so) retro gaming.
I don't know if anybody knows a mid-range receiver with correct aspect ratio processing for SD signal and better deinterlacing than a mid range Panasonic TV, and I absolutely hate any denoise processing that could not be switched off.(The 2nd condition is not that important)
I had a look with Yamaha receivers today, the outcome is extremely similar to my TV which is disappointing.
I did have some time with an Onkyo 607 in my friend's house, the aspect ratio is correct but the upscalling/deinterlacing is absolutely terrible. There is still not enough evidence to show every Onkyo receiver will check my 1st condition since they are with different video chips.