today itself i saw the 51 D490 in samsung plaza,....didnot give a much detailed lookout of the tv(went there 2 nquire abt the 51d550),...but the thing that struck me first was the extent of reflection on the tv...much like CRT'S(negative,particularly if viewed in some room where there is great extent of daylight entry & this 51"was not in display in some spl black ht demo room,rather some open area opposite of which were big whole room size glaas window panels through which natural strong sunlight was entering it) ....except that, i found the picture to be really great even on Sd tatasky which appeared to have been upscaled really well & then the 1080p Blueray source was really superb even it was on a display 1376x768 display. I went quite near the tv for any discernible hum,which i found not!.the tvhad great sound much better from the c series2010 models..better bass mayb the new introduction of srs sound system did the trick.Also the tv was royal & perfect in whatever degree u saw it,so absolute great there...these performance issues aside, i really liked the thin frame of the tv,menu interface was all similar to 2010 models & tv overall looked real smart,..aside from the 1 complaint of reflection/glare,which whoever i think should not be much of a problem if the tv is placed in interior rooms with less natural daylight/strong light entering & opted primarily for dark nigh time viewing!
Overall a very vfm pdp imho!
*yes,there r no goodies,..but the bad was there was NO supply of 2011 3d glasses till yet,for the lack of which i couldn't watch any 3d content on it & that's ne very important part of it!...though they did reassure glasses would be duly available once demand picks up!
i think now my 2cent review might b of some help!