The new Vizio M-Series for 2015 is a good budget 4k TV, and in some cases, even better than the P Series. As long as you don't expect a perfect TV, it is a good purchase.
The 2015 Vizio M looks higher-end than last year's did. It even feels slightly more premium than the P Series.
This TV has a very wide stand with cast metal feet. It is very sturdy, but you will need a table as wide as the TV itself.
The Vizio M is a very good TV for watching movies. The blacks are very deep, and very uniform. You don't have to worry about any judder while watching 24 fps movies, so Blu-rays, streaming movies, and other movie sources will all look great.
You don't get 3D or HDR (which brightens the lighting of highlights), but the local dimming, which dims the backlight for dark portions of the picture, works pretty well.
This TV's contrast ratio is great. The local dimming feature did have an effect on the black level of our checkboard pattern, but it also affected the white boxes, which isn't good.
As with the E series, the local dimming dims the highlights. It darkens brighter objects on the screen considerably when they are alone on a dark background. In our test video, you can see that the white dot is darker than it should be. Of course, there is less blooming that way, but it's not good to have the object appear too dark. The P Series handled our test pattern better, and it has more zones, too.
With solid colors, you can see some dirty screen effect caused by the full array backlight. There's also a pretty significant amount of deviation to the uniformity.
This TV loses saturation when you are off-axis.
Update 01/06/2017: We have changed the methodology of testing. Since this is an old TV which we don't have anymore, we extrapolated the results from 2016 TVs.
The black uniformity was great, even when local dimming was turned off.
The white balance calibration is really good by default under the 'Calibrated' picture mode. However, the colors are a bit off.
The red and blue colors couldn't be completely fixed, but the rest is great.
We had to increase sharpness to 25 for our 480p test, as otherwise it was really blurry. See here for more details. The P Series didn't have that issue. The noise reduction features work, but they are not very effective. Also, setting 'Reduce Block Noise' to 'High' resulted in a drastic loss of sharpness, so we used Medium instead.
Upscaled 1080p content looks a lot better than on the P Series, under the exact same settings.
It reflects an average amount of light.
It can get bright enough that it should be able to handle almost any room.
The screen has some darker patches, which could be a bit annoying when you're watching sports.
This TV also has more blur than is ideal, but that shouldn't be a problem for sports.
Unfortunately, like the P Series, this TV has a very long trail following moving objects. In our picture, you can see that the brighter trail even continues outside the picture. This shouldn't be an issue with normal content, but it could be a problem for video games.
The sub-par motion handling is more obvious when gaming, so the Vizio M isn't the best choice for gamers looking for great picture from their TV.
The delay is very, very low, though. If you're less concerned with the look of the game and just want a TV that responds quickly when you input a command, this is a great option.
The input lag is really low when using the HDMI 5 input and turning on 'Game Low Latency'.
It doesn't support chroma 4:4:4 unfortunately at any resolution/refresh rate. This doesn't matter for movies or even video games, you will only see a difference for a PC monitor. 4:2:2 works though.
1080p @ 120fps works (although only for the 60" model and up), which is great for gaming on a PC.
HDMI port 5 behaves differently from the others. See our Additional Review Notes
The sound is fairly accurate, with little distortion at normal listening volumes. Louder volumes do get quite distorted, though, and the accuracy suffers.
This TV's bass isn't great.
Note: Sound Quality test for TVs reviewed before 2017 was performed at 75dB, 85dB, and Max SPL. Starting 2017, the target SPL levels have been changed to 70dB, 80dB, and Max dB SPL.
Relatively good frequency response and loudness. However, at higher volumes, the frequency response gets worse and pumping artifacts may be present. The bass extension is not the best.
Low distortion at lower volumes, but the distortion becomes significant when the TV is pushed hard.
Vizio's app selection is limited, as is its codec support. There is no web browser.
The back of the remote is a QWERTY keyboard, which is handy for inputting text. A smart remote like you get with higher-end LG and Samsung TVs would be better, though.