QUOTE(putih @ Feb 22 2010, 01:53 PM)
And sometimes I feel that 508XG has more light output (brighter) hmm...

Between 720p & 1080p, difference can be seen if you're seated around 7-8Ft. If you're seated further than that, our naked eyes can't tell the difference.
I believe resolution wise it has max out at 1080p. In other words, it should be future proof (fingers crossed)
Unlike the Philips Cinema 56PFL9954, that is scaled up to cover the 21:9 resolution. The top & bottom of the image is cropped, thus affecting PQ.
If PQ is not a concern, the resolution does offer a really good cinematic experience