For a plasma to run at peak you'd have to have it in torch mode with the contrast turned all the way up. That would burn my retinas off. I still like my plasma (4 years old) better than current LCDs. It probably costs a couple dollars a month more to run one although I can't tell any difference in my electric bill when I have it on all the time and when I don't. (I have it set in user mode with the contrast about 25% of maximum).
My advice would be:
Don''t go to showrooms to compare picture quality. That tells you very little.
Take professional reviews with a grain of salt.
Consumer reports is worthless.
Best web site for learning more and the best user reviews: AVSforum