plasmas are far superior to even the highest end LED tv's in picture quality and refresh rate. the problems that come with plasmas are, in my experience you can sometimes notice the frames cycling, especially with indirect viewing. burn in is still a problem, despite people saying it isn't...it's definitely a LOT better than it was, but it's still there...leaving netflix on too long or watching cartoon network for hours on end may pose problems to your 4 figure TV set...and it isn't warranteed on any plasma set. they're also dim as compared with LED's...(as someone said though, i find they're better for viewing at home, and they look very dim on the walls of a super bright best buy or something similar...).
i was going to go for a panasonic ST60 plasma, but due to its input lag, and select few reviews stating that they experienced burn in on their sets, i've decided on the vizio m601-a3r. nowhere near as good a picture as the panasonic, but a very good picture nonetheless, same price point, much better input lag, thinner, more energy efficient, and no burn in to worry about.
the 80" vizio is also a great looking set, you may want to take a look in-fact.
also, most higher end TV's are 120hz, even though standard sources in the USA are 60hz, the TV's processor will slip identical frames in between the real frames, which smooths motion blur and jutter. 240hz is used in most if not all 120hz TV's in 3d mode ONLY. they market them as 240hz though, because that's their max capability. you'll find on any TV you buy these days what's called "soap opera effect" mode. useful for sports, but that's about it. watching movies on it is terrible (most TV's come with this mode enabled btw), it eliminates the small amount of jutter in the background blur, as well as sharpens the background blur, which makes things look like backdrops. some movies are unwatchable (i have a samsung 46" that i hated, until i turned the SOE mode off). all it does is insert identical frames between the real ones to smooth out the motion. just an FYI.
also, if you want the best of the best, in that price range, look at the panasonic ZT60 panel. they're being discontinued next year, never to be made again...simply the best picture quality available...period. but plasma...so there's that...