I have used several plasmas over past few years due to an ongoing problem in my area :
http://www.hifivision.com/television/22461-open-drain-affecting-plasma-lcd-tv.html
With my plasma sets used as normal tv, I never faced any problem of burn-in. Meybe a slight IR but it is very very temporary. I have never used any screen washing modes to correct IR. Even Tata Sky logo does not leave any IR. I watch long tennis matches .
In normal tv viewing , I think every one changes channels during breaks so this mitigates the burn-in problem (if any).
On the other hand PQ is the most important thing in the tv and according to me the black level is one of the most important component of PQ. Also viewing angle is a major consideration in PQ. In both these areas plasma is better.
I have not compared plasma with lcd or led so I cannot give my first hand opinion on this but my neighbor has a sony lcd as well as a panasonic plasma . They say that pictures on sony has pixelisation & look cartoonish whereas on panasonic life-like. They prefer to watch panasonic. Panasonic was 10k cheaper with b&w than sony which was bought from grey market.
In conclusion I can say that at a price range of 30-40k benefits of plasma far outweigh any cons .