Picked up the M55 at Sam's ($998) on Monday and fist impression is it's stunning. Conditions for me are a basement with one window to the side with proper treatments, viewing distance is 10 feet. Set is wall mounted with the middle of the screen a few inches above eye level when sitting. Settings out of the box are serviceable but like most others have stated it does take some tweaking. I tried Dr.Shankenstein's settings on Calibrated Dark but just didn't look right to my eye, everything looked muted on my panel. I'm still looking for the sweet spot but getting close with the Calibrated setting. World Cup qualifying last night looked good with no ghosting or motion blur. The same with NHL on Monday but did notice just a slight dirty screen effect when the camera was panning down the ice. I have not noticed any banding. The real test for me will come with football, I'll have to look for some game replays on the NFL Network. Not a fan of the NBA but the highlights on Sports Center look excellent to me. Non-sports programming (Discovery, Science Channel, HGTV, A&E, local news) have all looked good. Can't say what SD programming looks like, refuse to watch it as most of it looks like garbage to me.
Looked at the first fight scene between Bane and Batman on BD and the contrast and black levels were great, smart dimming was effective and not an issue. Tron Legacy would be a good test but I don't have a copy.
3D through the YouTube app was excellent. This is my first 3D TV so can't compare it to anything but Avatar 3D at the theater and the experience was the same, definite wow factor. Haven't seen it mentioned before but Galapagos 3D is a great way to show off what this set can do. I'm connected through wifi to my router and get 10 Mbps speed from my ISP (local outfit, Falcon Broadband) and it's adequate for YouTube. It paused for a few seconds a couple of times to load during the 10 minutes I watched of the Avatar 3D trailer but the Galapagos video played all the way through smoothly. No subscriptions to Netflix, HULU etc so can't comment on those apps.
Played Black Ops 2 on XBox 360 and noticed no difference lag wise from my last set, 6 year old Sony Bravia 40" LCD 8ms response vs. the 5ms response from the M55, which is virtually non-existent. Any lag I see is a limit of my ISP (at least that's how I justify my poor play!).
The remote works fine for me with a clear line of sight to the lower left hand corner where the sensor is. The only button I find buggy is the up arrow but all others respond first time, every time. Hope the much talked about update this summer to wifi functionality makes the remote even better.
Tried the sound out and I would say it's only adequate for the local news broadcast but not much else. All sources run through my Denon 1613 receiver via HDMI. I have the ARC enabled so sound from the YouTube app was routed back to my receiver via HDMI with no problems. The volume control on the Vizio remote controls my receiver as well.
Received the firmware update to 1.04.955M90 first time the set was turned off so must have been in a batch previously scheduled for the update.
The picture and performance are excellent, I couldn't ask for any more bang for my buck. Will you find flaws if you look for them, yes but I'm sure that's true of all edge lit panels (at least that's what I leaned from the AVS forums). My review and impressions aren't based on scrutinizing still images, start up screens or movie credits but from watching a wide variety of content. My M55 provides an immersive experience and I think that's what most are looking for in a TV.