I've been following the chatter about the 42" Westinghouse for a while. Also have a 42" and 50" Panasonic 8uk for client monitoring at our studio where we do professional HD color grading and digital intermediates. Some of our clients are New Line Cinema, Fox, Discovery, Universal, Lion's Gate, so we're exceptionally picky about colorimetry characteristics. To compare anything to the Panasonic Plasmas is sensible--although a different picture distribution medium altogether--considering the professional level of control over picture quality and the picture quality itself.
After months of handwringing research, we decided on the 47" model versus a 50" plasma of lesser cost and better viewing angle, because of the multiplicity of inputs, true 1080i/p, energy consumption, heat index, total weight, scaling support electronics, and the willingness of Westinghouse to support serial returns if there are defects. Although I'm not sanguine about ordering a 3+ meter delicate panel 2500 miles away from Hollywood, I went with Crutchfield based upon their reputation, level of customer support, return policy and the fact they had these in numbers.
There are a number of tests we perform on monitors to keep them up to calibration. When we get it I'll let you know what we think.