I'm in DC so I have not familiarized myself with recent advancements in altitudes effect on plasma.
Burn in CAN be an issue, but rarely is unless you play a fair number of video games. Plasma is still considered the winner for motion video. Better image quality all around is the verdict with LCD still having a ways to go. LCD will eventually be there, but plasma, in my opinion, is still the way to go, especially with how many options are available to you.
REALLY THOUGH: LCD does look great, just a smidgen worse than plasma, and even that depends a fair amount on what you are watching. As I said though, burn-in is all about LOTS of static images on the screen for hours. We press 'pause' on our plasma for our DVR and leave it there for an hour at a time and it has caused no visible ill effects, so I wouldn't expect people who just watch TV to have issues either.
Lots of videogames... well, then I would think about it a lot more.