I do a lot of gaming on my 436 and it is excellent, no smearing or bluring. I've got my Xbox modded so it outputs an NTSC Progressive scan picture and am using the official MS Hidef AV pack available from your importer or ebay. The Picture from the Xbox is fantastic, especially on those few games that make use of the 720p mode.
I've tried my PS2 using component and using RGB scart and could no tell the difference, so am sticking to Scart for now until I get my new amp which will have component switching built in, again the picture is pin sharp.
Last night connected up my PC to the plasma and again totally pin sharp display, just need to raise the funds to buy a Shuttle PC or laptop so I can view HD content from the PC, surf the web and do a bit of gaming on my big screen.
You will not be disappointed. I've also had no issues which image retention, but I keep my gaming down to 2-3 hours a time whilst I'm still running the set in.
Used the front VGA socket, it was only a test as I've only got one very noisy tower PC. Using VGA on 1024 X 768 it looked to my eyes as if it was pixel to pixel mapping, no overscan or borders. 1280 X 768 worked but windows text lost some sharpness, how I envy those 506 owners....
Me to mate. Really pleased with my 436 tho'. Going to try it via DVI but I need a convertor cable and apparently I need to channge the output setting on my GFX card to 'video' - Watch this space - I will let everyone know if there is any noticeable difference. How you got your sound configued or are you using your PC speakers?