Back in December 2011 we reviewed the, a 3D smart television that offered decent performance and features for the price.
The only thing we didn't really go for was the 3D implementation--it was a little strong, resulting in unnatural images, and couldn't be dialed down. If 3D isn't important to you then Vizio's dedicated 2D set, the 55-inch M550SV, may be of interest to you.
While we haven't tested the M550SV, a quick perusal of the spec sheet shows most of the same features as the M3D550SR, including Smart TV in the form of Vizio Internet Apps--including Netflix and Hulu Plus--and the reversible QWERTY remote.
The M550SV is an edge-lit LED, and while it also features local dimming it has a lower "dynamic contrast ratio" than the 3D model. If you watch sports, the 240Hz refresh rate may be beneficial, but it's not something we recommend for movie watching. Four HDMI ports and onboard 802.11n wireless round out the package.
The only mystifying aspect of the Vizio Razor M550SV is the price: it's the same as for the 3D model, which not only has 3D but a supposedly better contrast ratio. As a result, the M3D550SR may represent better value.