Mits WD52631 owners ??

I bought one of the first ones in August.
My take is-

Good:
Really bright screen with good anti-reflection, works fine even in broad daylight with a south facing picture window and the lowest brightness picture mode.
Outstanding color range and fidelity
Good price value
Strong over the air receiver
Picture quality about as good as the signal you feed it. HD from cable or over the air, and XBox360 are terrific.
Overall physical size minimal for a 52" screen. This was the biggest screen I could fit into our entertainment armoire
No blur on action scenes or video games, or delay in video game response or sound.
Geometry looks fine
Quick lamp start-up mode uses more power but allows the picture to come faster on power on, and you can turn the TV off accidentally and still turn it right back on.
I never see rainbows on DLP, but for what it's worth no-one else who has watched the TV has seen them either ,even in extreme conditions.

Not so good:
Standard definition looks bad on HD sets, and to my eyes, the Mitsubishi sets seem to strive for max picture sharpness so a bad SD signal looks really bad on this TV.
Shadow detail is fine for most dark scenes, but when you get extremely dark scenes it is not quite as good as some of the sets such as the Sony SXRD that have better contrast and variable irises
The side connections are composite video instead of component or HDMI, so I have to snake cables around from the back to connect XBox 360

Notes on set-up:
Set picture to lowest brightness, which is Natural. I can't imagine anyone ever using the other settings Bright or Brilliant, they make the colors look positively cartoonish, and are bright enough that white scenese will have you screaming and fumbling for your sunglasses .
Set color temp to low, otherwise way too blue, then adjust colors to make the whites white again.
Set Contrast to high, it seems to improve the shadow details.

I also own a 52631 which I've had for about 6 days. So far, I love it. Leggs mentioned most of the info that I would mention.

One additional point: I do notice a slight hum coming from the TV. I believe this is the color wheel spinning and it doesn't overpower any other sound but it's noticeable when there is no other sound (for example, when you're fast forwarding a DVR or mute the TV). I also noticed that it is only noticeable when the TV had been on for a while.

I have read other threads about this issue and am trying to decide if I should exchange the TV or not (for the same model) to see if it's the entire line or just my TV.

Other than that, I love it.

I've had my Mits 52631 since the day before Thanksgiving. People are still blown away buy the HD picture. I'd buy it again.

The SSE seems unavoidable in any RPTV, I think it is a function of the screen construction which has "gain" : that is, it is designed to channel light forward to maximise brightness. The Mits seems to be better than average, perhaps because they use a very bright lamp so the screen material can be made with less of this gain.

I can hear the hum which is loudest near the ventilation output, and am not sure if it is the color wheel or the fan, or a combination. The color wheels spin at very high RPM, I don't know what it is in this set, but generally DLP wheels spin at 10,800 or 14,400 RPM. At that speed the noise would usually be very high-pitched so based on this being more of a low whoosh and where it is coming from I suspect most of it is the cooling fan. At any rate, the sound is drowned out by the hard drive and fan in my DVR cable box. The cable box is several times as loud and sitting in the open while my TV is inside an entertainment unit.

The only serious deficiency in the picture is due to the inherent limitation of the signal. The finest HD channels such as Discovery or PBS look great, but even with those, if you look closely you can see the video and compression noise that comes from the fact the signal rate is limited in bandwidth. I almost bought the Sony SXRD because the three overlapping LCOS chips seem to soften and smooth out the picture noise. Even with a 1080 upscaling DVD player I can see the deficiencies of the DVD format. It will be nice when the HD disc wars settle out, or the combo players get cheap enough that I can start buying HD or Blue-Ray discs. The improvement is worth the extra cost.