I read a report once that indicates that these second tier vendors (Vizio, Insignia, Polaroid) have more issues and especially poor repairablity after the warranty period. Basically, if it's after a year and it breaks, toss it.
I would only buy the major brands -- Panasonic, Samsung, Pioneer, etc. I'm sure they have their problems as well, but they are stronger and have better support. I recently bought a Panasonic plasma at Costco, and did not even consider Vizio.
The report I read (can't remember where now, but it was referenced from a couple forums; I might have even posted the link on this forum at one time) was from service guys, and was not just a slight on those manufacturers.
OTOH, I'm sure there are lots of guys that are happy with Vizio, etc. If you want to take it back, I'm sure Costco will take care of you; they've been great with us.
Good luck.