What worries me most is that there is no way to get parts for these TVs if they die outside of "return with the box" warranty. A TV is an investment, and like any other investment, most people want to be able to depend on them. If you can't get it repaired if it breaks down, it's more of a money sink if it does fail.
I have nothing to say about the picture quality of those sets as I have never seen one on anything other than the crappy local Walmart's split 25 ways analog coaxial system.
Though if you want to consider the long term, I would suggest LG and JVC over Samsung. The prices are not much different from Visio and Olivia now due to the price wars and cheaper manufacturing processes. However, be wary of the LG LB7 models, ask the dealer if they've been repaired as per the recall yet. Apparently the manufacturer of the video board put the wrong resistor in somewhere and it fails and so does the output section. Simple repair though.