I've got an Acer LED 23" monitor. I've found it took a bit of playing around with to get the colour settings right, but its a huge improvement over my old dumpy 18" CRT. In comparison to the Asus LCD monitor sitting next to it, I find the colour quality is comparable, maybe with a very slight favour to the Asus, but the blacks and darker areas in general are much richer on the LED screen. Since it seems to be newer tech, I figure its just a matter of time until it's refined to be better than traditionally backlit displays all around. The LED monitor is much thinner than the LCD, which helps for moving it around (Done so 3-4 times for LAN parties/just moving the computer) but most people won't find this to be a key factor. Same goes for the power consumption, which is apparently much better with LEDs too.
Basically I'd say they're pretty much even, with the largest disparity being between brands and models. Granted I'm going off of a pretty limited sample here, but since the LED was cheaper by about $40, and still competes in all areas, I would say that they're pretty good.