Hi, as i recently bought plasma TV i an say it has some issues.. First of all You definitely need to have light controlled environment, as even best plasma's can lack brightness in bright room.. I sit in front of my plasma and if curtains is open i always can see myself like in mirror
But when it is dark picture is superb.
Are You interested in 3D? as there is even more questions, i have issues with it, and maybe could help You with some advice
What about input lag, You should check every TV model and look for review, as they really do test input lag.
And about the refresh rates, if keep it simple if You have 60 FPS and 60Hz it means your TV shows 60 frames per second, and on 120Hz TV shows 120 frames per second creating additional frames to fill it up to 120Hz, picture should look smother annd with less flicker. Plasmas 800..3000Hz have a lot of marketing, check this article http://reviews.cnet.com/8301-33199_7-57524894-221/what-is-refresh-rate/