Well, I've had my 50A10 and here's my take on things:
[With some second day edits to address a mistake I made, and to note a couple of other things.]
My Setup:
HD/Big Screen Experience: None. This is my first HDTV and I've never watched anyone else's HDTV/Big Screen TV. The 50A10 is replacing a 32" JVC CRT I've had for about 10 years.
TV: 50A10 (duh)
Cable feed: Basic cable package from Wideopenwest (analog channels from 1 to 100, basically) with cable directly connected to TV's cable coax input (i.e. no set top box, no CableCARD).
DVD: Toshiba DVD player - NOT progressive scan. Connected with component cables.
HDTV: I'm using an antenna I mounted in the attic about 20 years ago when I first moved into the house and before I got cable service. It is connected, naturally to the UHF/VHF coax input on the TV.
Sitting area: 9-10 feet away.
Aesthetics: Great looking set. But that 3LCD sticker is coming off on day 31.
As noted there appears to be a slight up and down wave of the baffle below the speakers but, it's hardly noticeable and generally symmetric - on my set at least.
I have it on a 43.5" wide stand (Tech Craft MT400) and it fits on there very nicely - the 1.5" overhang on each side looks fine.
General PQ: I see SDE a good amount of the time. But, I'm also looking for it. Time will tell if my brain is eventually able to filter it out.
[Day 2 edit: Mr. Brain appears to be activating the SDE filter a bit already.]
I would definitely be fine with the 42A10 in this regard given my sitting distance since watching the 50A10 from a longer distance, say 12-15' shows no SDE. But, I'm digging the big picture of the 50. But, I got another 29 days to decide whether or not I can live with it.
That said, the colors are very nice and vivid even with toning down some of the settings.
And, finally, I do need to at least run a calibration DVD through the system.
Cable feed PQ: Looks fine. Some channels better than others. There are push and takes between the A10's PQ and my old TV's PQ. In other words, the A10's picture has some issues with it that are different than the issues with the CRT picture. These different issues cancel each other out over all, and to be honest the bigger screen A10 makes it easier to see these issues. The problems are basically blurriness or maybe its a form of ghosting or blooming of colors - maybe I need to turn down the colors a bit more, I'm not sure. I also notice that some text doesn't look very good while other text displays look pretty good. I find that kind of annoying. Anyway, it's that sort of thing I'm talking about and is probably something I just have to learn to live with. But, it will require some more couch time to decide whether or not I can get used to the standard cable PQ on the A10. And, this is pretty important since we watch alot of standard cable shows. I don't think going to a digital cable package via a CableCARD will help since I think the channels I watch now will still be analog. But, I might try it out and just cancel the service if it doesn't do much for me.
DVD feed PQ: [Edit: I had forgotten to change the setup on the DVD player to account for a 16:9 TV - it was still set up for 4:3. This change made a HUGE difference. The TV seems to do a fine job with my DVD player's 480i input over component cables.]
HDTV: Only saw part of one show that appears to be a "true" HDTV broadcast and that was a show on PBS. It looked *very* nice. Some pixelation during some fast moving scenes (PBS broadcasts in 1080i which may account for this). But, it was really nice to look at. Very enjoyable. I also, looked at some "normal" broadcasts being shown on local HDTV channels (e.g. noon-time news) and they looked pretty good, but not that much different than what I see via my cable connection.
(For you Chicago western suburb folks, channel 2 is basically worthless which is currently the norm for this channel. Though I understand they are moving their HDTV up to a higher frequency which should help.)
[Day 2 Edit: Channel 2 is actually coming in a bit better now. Also, I watched Law and Order and some Leno in HD and it was really great.]
Summary: Am I gushing over the set? No. [Day 2 Edit: However, with my DVD setup correction, I feel some gush forming.] Am I upset about the purchase. Not at all. Are my expectations too high for a $2000-ish set? Maybe. Will I keep it? We'll see. Am I going to get a bunch of couch time with the TV? You bet. Will I bend your ears more in the future? Yep.
Mitch
I thought I was going nuts also. 
