I just picked up the 51" D550 at Sears on Saturday and finally got a chance to hook everything up. So far I'm definitely impressed with the image quality of the tv. My other set also happens to be a Samsung plasma, a 5884 that has produced an absolutely breathtaking picture since I purchased it a few years ago. The 5884 was too big for the nook in the living room when I purchased my house, so it got relegated to bedroom duty. I ended up getting a sweet deal on a Sams Club auction for a Pioneer 5010 over a year ago, but the unit arrived with a cracked screen to my horror.
The nook remained empty for over a year until last weekend.
A few negative impressions:
I love the looks of the tv, but I didn't like the way the screen mated to the base. I found it a pain to attach.
The screen is definitely more reflective than I had anticipated. I rarely watch tv during the day (if it's on it's for background noise), so the reflectivity is a non-factor for myself. If I were a daytime viewer, I'd get a 7 or 8000 series for the superior anti-reflective screen.
The streaming was meh. I much prefer using the PS3 for streaming duties. I use a wired cat6 connection throughout the house, but found the D550 to be a little slow with a somewhat clunky menu system. The PS3 is smoother all around for me, though I'm still playing around with the D550, since there is some content I just can't seem to get streaming properly with the PS3. I use TwonkyMedia Server.
Buzzing is inaudible at the seating positions in my living room. I had to get pretty close up, i.e, within one foot of the set to hear anything.
Everything else is all positive in my book. Sears included 2 pairs of 3D glasses free with the tv, so while I've never really been too intrigued with the whole 3D thing, I've got to admit the 3d demo games I downloaded from Sony PS Store looked awesome. Haven't seen any 3D movies yet, I can't really comment there. Speaking of 3D, the manufacturers and studios are ruining their own product with this 3D title exclusivity crap they are pulling. The lack of titles is also frustrating.
Can't wait until we get some reference picture settings posted!!!