I bought this set about a week ago from Costco (was originally looking at 60" tvs from Samsung and LG, but was intrigued by this). When comparing the sets next to each other in the store, the Vizio had a sharper picture with less blur compared to the Samsungs, Sharps, and LGs around it. I was always skeptical of the Vizio brand, but CNET rated the picture quality on other sets fairly highly, so I took the plunge.
First off, this thing is huge. Maybe its because I came from a 40" tv, but holy crap. LOVE IT. As for the picture, out of the box, it was ok. The colors seemed a little dull (not like what I was seeing in the stores) but was fine. I took out a DVD with THX and used their calibration options from the settings menu. That definitely evened out the colors, but still had them look soft. I found the "color enhancement" option in the video settings and set it to "normal" and that did the trick. Right now, it looks pretty sweet.
I haven't noticed any banding on my set as was previously mentioned in this thread. However, I can confirm the speakers do suck on this set. I have some floorstanding speakers, so it isn't an issue for me, but I could see how it would be annoying others. The menus are a little slow to pop up, but it's minor annoyance. The only real issue I have with the tv is that there are not a lot of inputs. If I had a better receiver, this wouldn't be an issue, but the fact that is shared the component input with the composite means I cant hook up my n64
As for gaming, I've been playing Black Ops 2 on this, and the picture looks great. The only weird thing I have noticed is that from time to time, the video connection cuts out for about 5 seconds hen reconnects. I think this is an issue with my video passthrough on my received, but I''m not sure as it doesn't happen to the cable box ever.
Overall, I am happy with the tv, its ridiculous size, and its fantastic price.