I have the 57WS550. I have not seen the WS510 model. I have read several posts over at AVSFORUM where someone has stated that the 550, as well as having the ATSC tuner, is a new chasis with several improvements over the 510 (same guns though). You might take a trip over there and scout around for information. The 550 apparently has a better anti-glare screen - again, I can't comment - just passing on information.
BTW - I thought the 510 downconverts 720P to 480P.
Here's one link I was referring to (am I allowed to do this?????)
http://www.avsforum.com/avs-vb/showt...ighlight=ws550
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