Overall, Magnavox televisions tend to look much better than the Vizio sets. Sitting side by side, there is a pretty noticeable in not only sharpness and clarity, but also in color. The Vizio tv's tend to tint colors a little warm (everything seems to have a little bit of a reddish tint to it). The color accuracy in Magnavox sets seems to be a quite a bit better than the Vizio sets. The only two things that Vizio has that Magnavox does not is (typically) a lower price and a better warranty.
I would advise going into the Sams Club that you bought your tv at and asking if you can see both the 47 Vizio and the Magnavox tvs sitting side by side. The Magnavox will be brighter, the blacks will be blacker, and the flesh tones more accurate. In addition, another downfall to the Vizio tv's is that they don't display an analog picture very well. Because the Magnavox has a higher quality video processor in it, it tends to have an overall better display.
Hope this helps.