As an owner of a Samsung HP T5054 and former owner of a Vizio 42P I can say that the Samsung has a much better picture, but I do like the PIP feature of the Vizio better.
So far as the garbage doogie is shoveling, I don't know what was wrong with the Samsung he was watching but it's certainly NOT something that's been seen by myself or other owners of Samsung 5054/64's I have not seen complaints such as his on the Samsung 54/64 threads.
The Samsung does have an odd quirk that is soon to be fixed by a firmware upgrade in the works that creates a little jump in the screen only really noticeable on things like news tickers and slow horizontal pans, though it's very hard to note in the slow horizontal pans unless you really look for it.
I really enjoy my Samsung HP T5054, I bought mine when they first came out, and though I paid far more then than they are sold for now, I would still buy it again and feel I got a really nice TV. For the price they are now they are a great deal in my opinion.
Oh, and I watch my Plasma about 8 feet away from the screen. I have watched it from 6 feet away, and if it wouldn't make my living room useless for more than just my TV viewing, man I'd never view it from further, looks awesome even at 6 feet.