Bought a 47WT50 but had to return it due to a huge backlight leaking spot on the top edge.
Had the 47DT50 before, absolutely loved the picture quality and easiness of use, returned it because the black level was not good.
Just ordered the 55DT50, like new, for $707. After some research and comparison, I decided to put up with the poor black level. (1) I won't notice it unless I am watching a movie in a dark room, (2) I will never get good black level and contrast ratio until I get an OLED TV a few years later.
DT50 is exactly the same as WT50, except lack of local dimming and dual core CPU. Dual core CPU has no impact on picture quality, it only speeds up smart apps which I do not use.