I got my Vizio M-55 today and I promised I'd give some people my impressions. From the second I turned it on, I could tell the black levels were much better than my old Samsung led set. Also, I couldn't detect any light bleed either from the edge of the screen or within the screen itself. The setup was alright, but I had to do all of it with an android tablet that came in the box. More on the tablet later. Also, only one input has hdmi 2.0, but I don't think that's a problem for the price we paid.
Since we don't have a uhd bd player yet, I popped in uncharted 4 and enabled hdr mode. I was greeted with a disgusting puke-green picture. It turns out I needed to update the tv's firmware a second time, but I didn't see an option to do it. I guess it can only update when the set is off, so I turned it off for a bit and it downloaded the update pretty quickly. After that, everything looked great. I played the last chapter of uncharted 4 and the colors looked pretty damn incredible. Not as good as the ks8000 my friend has, but definitely in the ballpark. Input lag seemed fine at first blush as well, but I'm not that sensitive to lag in the first place.
Well, when it came time to watch some 4k content, I had to use the included tablet to use chrome cast to play any streaming apps. This seems like a good idea, and it's fine when it works. Unfortunately, the tablet is a bit cheap, but it gets the job done fine...when it works. I had a few problems trying to connect to Netflix, but i just had to hard reset the tablet to get it to work again. Luckily it looks like you can also cast with your phone, including iOS, and that seemed to work fine for me.
I don't think I can comment fully on how the picture looks before we get a bd player, but it's pretty damn good from what I've seen. The set has terrific black levels, but I only wish the whites were a bit brighter. I watched a bit of Marco Polo on Netflix, and it was pretty fantastic looking. To avoid spoilers, I'll just say it was a scene with a lot of fire. The lights from the flames weren't blown out and I was amazed at how great the details in the dark background were.
Those are just my initial impression, but I have to say I'm totally satisfied with the purchase. Now I just need to calibrate it. Oh joy!