When I selected my HD set I did alot of comparisons and decided that sports was my main motivator for HD. I spoke to some friends who are buyers for a electronics chain and the consensus was that DLP/LCD had longer longevity but was not as good for sports due to the slower response times. With LCD some fast moving images would 'trail' or pixelate. Plasma was better for sports, but could have burn in issues, so not good if you want to play video games on it. I never see trails on my Sony Plasma, but my friend who bought a Sony LCD Grand Wega projection set does get trailing on fast moton.
Here was a portion of a review I read on a LCD set and the information on refresh rates:
The second drawback of the unit is a motion trailer effect, which is prevalent in most LCD TVs. This is caused by a signal response time which XXXX claims is 15 milliseconds compared with a plasma display which has a signal response time of 7 milliseconds. On almost all LCD TVs fast motion scenes can display some trailer effect and that is true of this unit as well.