Had the UA50EH6000 (in New Zealand) for few months now and thought I'd share my thoughts on it since this thread was helpful for me.
The actual model is UA50E6000M(XRD) and the Panel is a CH01.
My setup involves a Pioneer receiver with output going to HDMI 1 and inputs coming from MySky receiver, DVD, PC/laptop. I regularly play divx/x264 (in both avi and mkv containers) from the usb port without issue. I also have an optical cable running from the TV to the receiver for better audio (than internal speakers) when playing USB content.
I use a Logitech (3-in-1) remote to control the receiver, mysky and TV.
I'm not very picky about everything, but I do notice some issues which may annoy others.
A few notes/observations so far:
* Compared to other TVs at the store, red seemed a bit washed out. This confirms many of the reviews out there about the redness. However, after watching it for this long, it doesn't seem to be too bad.
* On a completely white screen, you can notice slight darkness around the edges. This is probably normal since it's not a fully backlit panel.
* When switching between inputs or channels (when the screen has no signal), there is a noticeable grey vertical line pattern that seems to appear on the left side of the screen. I haven't noticed this on the other side of the screen, but it always does seem to stick out on the left half in one particular spot. That said, that seems to have no effect on the picture quality when there is an image on screen.
* When playing .avi content through the usb port, there's always a point where the audio just dies for a few seconds and reappears. I think this might be specific to divx encoded files since I haven't noticed it on x264 video.
* In some cases when there's a close up shot to someones face, it's easy to notice lip sync issues, but this is not consistent throughout all video I've played on there, so I suspect source problems. I have SPDIF latency set to 0ms.
* The TV *does NOT* support ARC even though my receiver does, that's why I needed the optical cable.
I haven't really calibrated this in any serious way, mainly using the settings posting in this thread and whatever improves image quality when watching TV/DVD/USB. Most of the content being watched on there is either SD/DVD or 720p over Sky (DVB-S). It looks pretty decent and I haven't noticed any annoying blurring or choppiness (which I do notice when its from the source). I've also hooked it up to my PC and played 1080p content, which looked great.
Overall, I think it's a good TV and I got a 5 year warranty, so can't go too wrong really. My first choice would've been a plasma, but given the circumstances, I thought a backlit (albeit not full) LED would be best. IIRC, I think my backup if this one looked bad was a Samsung PS51E531.
If there are any specific questions, let me know and I'll try to help out as much as I can.