kde, you have gotten a lot of great information.
As someone who just took the plunge a couple months ago, I can say that the Sony XBR I bought was the best investment I have made in 25 years. Of course, it was 25 years ago that I purchased my last Sony XBR-KV25. I got one heck of a deal on the previous model XBR-46HX909. It isn't quite as thin as the new XBR-46HX929, but will do in a pinch. I have to admit, only paying $1099 for it really helped me make my decision (instead of the $2499 it originally retailed for).
I have to say, that if my main objective was to watch 3D, nothing I have ever seen, compares to the Plasma sets I saw at the local Magnolia center at BestBuy. I have heard nothing but great things about the Kuro displays, but don't ever think I have seen one in person, that I know of. The LED does make a big difference in the picture quality, as does the local dimming that the Sony XBR models have. I'm not a big fan of Samsung LED televisions, only due to their inherent glare from the screen in a room with windows. As for picture clarity, the Samsungs, in a dark room are probably superior to the Sony's, but I prefer a little less glare on my screen.
I was almost swayed into going with one of the better Panasonic Plasmas that I saw at BestBuy, but, when I started doing my homework on my next purchase, I still read numerous articles warning of possible burn-in with the plasma tv's. They all said the problem was getting better, and that manufacturers had built special circuitry into the plasma tv's to combat it, but it was still a problem last year when I began my search. I knew my old XBR was biting the dust after 24+ years in service. Of course, that TV was about $1000 back in 1986 when I bought it.
I am sure I haven't really said anything to add to the party, except you get what you pay for. If it wasn't for 3D, if I can get my hands on an older Sony XBR8, I would buy one. That was probably the best TV ever made. It was just too expensive to produce back in 2009. It had a TRILUMINOS® RGB LED backlight display, unlike the ultrathin televisions today. Talking to Sony reps recently, they admit that is was better than anything produced currently (at least by them).
Hope that helps.
SteveG