What is the difference between this and a 5090:
You can do a search on AV forum UK for some additional features which the KRP 500a has.
Pure cinema springs to mind.
Looking for more points of difference between the 500A and the PDP-LX5090, one of the main things is a new AV Optimum mode that uses an optical light sensor to automatically adjust the screen's picture settings according to the light conditions in the room and - get this - the colour characteristics of the ambient light around the screen.
Or see this review:
http://www.trustedreviews.com/tvs/review/2...in-Plasma-TV/p4QUOTE
Without doubt the single most intriguing string to the 500A's bow is the Pure AV mode. For it really does appear that if you use this mode with a high quality HD source, the resulting picture looks subtly different - in a good way - to the results achieved using a PDP-LX5090. There seems a touch more sharpness, a touch more authenticity to the colour palette, and a touch more ‘texture'.
I should say here that when I say ‘texture' I'm to a large extent talking about grain, but since grain is an inherent - and deliberate - part of many HD film transfers, the 500A is merely doing what it's supposed to be doing in Pure mode and revealing every last thing a source has got going on.
This fact makes me feel the need to stress that I'd maybe only really recommend the Pure mode with a HIGH QUALITY HD source. For the mode's inevitable ‘warts and all' tendencies mean that if a source has any severe weaknesses caused by poor encoding (and believe me, such weaknesses aren't as rare as they should be, even on Blu-ray discs), such as a curious colour palette, lots of dot crawl and/or a tendency to over-stress edges, in Pure mode the 500A won't be able to use its clever processing to actually make things better.
The 500A's knack for improving things extends to standard definition sources too, which look to my eyes slightly more stable and noiseless than they do on the LX5090 - and vastly less noisy than I'm used to seeing on many other Full HD TVs.
Verdict
Provided you're feeling flusher than most right now, all you need to know about the 500A is that it actually outperforms even its own sensational LX5090 sibling - and in doing so can justifiably claim to make the best better. In fact, I might even go so far as to call the 500A a Christmas cracker were it not very likely that Riyad would sack me for my trouble.