OK....I did get the budget-ready Westinghouse. The pic was definitely less sharp & vibrant, but still quite nice for my occasional dvd, mostly news watching. The relatively narrow difference in picture quality (to my less critical eye) did not reflect the far wider price margin.
Screen size depends on how far you'll be sitting. There's a zone of emotional/perceptual involvement that you have to be sitting within.....hence, the farther away to sit, the bigger the screen has to be. I sit maybe 8 to10 feet from the screen and find a 37" to be just fine.
More frequently, I sit about 16 inches from a standard sized book page and find that just fine for my bifocals. Cleaning my lenses and clearing my head does wonders for the picture image I get from within my head.