Interesting so how do LCDs produce more heat with half the power? Do they have some sort of perpetual motion machine in them? At work we had a lab that was all CRTs, about 20 or so, the air conditioning was running all the time, even during the middle of winter, we replaced them with LCDs and the AC only runs in the summer. AND the electric bill dropped to about 40% of the pre-lcd days.
They principle advantage of CRTs are in the dark greys and blacks, the principle disadvantages are power (and heat), size and weight. You pays your money you takes your choices. Since I pay the elctric bill in my house and since I don't watch all that much black on my TV or computer the choice is pretty obvious!
To recap the heat comes from the power, the more electricity you draw the more heat you produce.