Well at least no one has suggested getting a plasma 'refilled'. With regard to plasma lifespans, here are some facts.
1) Almost all new plasma panels are rated to 60,000 hours until phosphor half life. This includes most of the major manufacturers (Fujitsu, Panasonic, NEC, Sony, etc...). I don't know who makes the Daewoo panel, I am 95% sure it's NEC. Some new ones are still rated 30k hours, and most older generation ones are 30k hours.
2) Half-life does not equal death, it means the phosphors are half as bright as when they were first turned on. Will the TV be usable at this point? I don't know, probably but read the next one and determine whether you're even going to want to.
3) 60,000 @ 12 hours a day is 14 years.
4) A plasma has no moving parts, that means if the power supply doesn't die it will require no maintenance, no new bulbs, backlights, convergence fixes, etc.
In regard to their other merits, those are all highly subjective so you have to decide whether they work for you or not.