To answer your question my understanding is yes that is an effective way to check hours. Got that from avsforum in one of the plasma threads. I own 3 VT, 1 ZT, 1 ST, and 2 PZ800u sets.
they all work great. Make sure you have adequate power protection from surges as does not take much to fry the A board.
I much prefer plasma for everyday watching the motion is just so much better to my eyes. Have a Sony 385es for the movie room but used the VT for 8 years prior and was great .