I just spent about 30 minutes comparing the HLP5063W and the 525 at the local GG. Unfortunately, they didn't have them side by side, so I had to walk about 30 ft. across the store to compare images. Both were being fed with the same 1080i source containing a Discovery HD promo feed (although both were also connected to an OTA antenna that I used to check out crappy analog feeds - I didn't try the ATSC tuner in the Mits).
Screen door was visible on the Mits, not on the Sammy (due to the HD3 in the HLP). Like others have mentioned, the Mits seemed grainy as compared to pretty much every other TV in the store. I was able to set the HLP up in Cinema mode and turn the sharpness all the way down to 0 (bad sharpness, go away!). On the Mits, I couldn't figure out how to do the same thing easily. After cruising through the menus for a couple seconds, it looked like I had the choice between full "auto" picture mode or super detailed, adjust 6 differenct color values, mode. Since I didn't want to go through a full calibration, I left it on auto. Overall, I think the Mits had an edge in detail and black levels (although less than I would have thought), and the Sammy just looked smoother. The real deal killer on the Mits was the screen. It was practically a mirror! Might as well advertise "bright, shiny screen." I'm sure the 725 series is much better in this regard, but I didn't want to wait that long or spend that much.
In the end, I was able to get a fairly good deal on the Sammy with 24 months financing, so that's what's getting delivered on Friday!
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