Normally, what makes the Vizio so affordable is its lack of options and settings. Also cheaper less accuarate components. Not having correct math or compnents within certain strict guidlines, you may experience overscan and any other general picture issue. Older tube TVs were easy fixes, re-capping the set would take care of overscan issues. On newer sets, especially the value-line ones, you get the worst case scenario; cheaper parts and no options to compensate for their in adequacies.
If its within the return policy, i'd recommend a name brand set, possibly even a plasma if its a cost issue.
Hopefully that helps answer your question.