I bought a LG 55LE5400 a few weeks ago at wallyworld because the pq in the store looked great but when I got it home and set up I was very disappointed. Serious flash lighting around the edges and it had terrible lip sync problems.
I boxed it up and returned it and decided to take a chance on this M550NV, I'm glad I did, after it was in my home and set up the pq was amazing paired with Dish Network. Blu-Ray Avatar on my PS3 floored me, streaming HD from the net is flawless with the built in Wi-Fi, I assumed I would have negative results with wireless, I was SO wrong.
Set-up was a breeze and it detected and updated the firmware within minuets. Some of the apps are pretty useful, the rest I deleted.
The one thing I hope they incorporate is the ability to play divx / mkv files from the USB ports.
All in all this Vizio is a total homerun.