LED LCD usually gives you better and more uniform colors, better contrast and lower power consumption.
I have 2 LCD's a 19"monitor(2ms) and a 32" Samsung LCD TV(have no idea how many ms) as a main monitor. LED LCD's are more expensive.
There are more types of LED panels, the most common are with LED back light behind the hole panel or at the edges.
As for 2-5ms the difference is too small for most people to notice it.
Wish i had a 32" LED monitor(panel made from LED's, i mean).
5ms Displays Usually Have A True 8-Bit Panel, Most "Accelerated" Monitors Are 6-Bit. LEDs Will get You More Accurate, More Uniform Colors And Better Contrast, If You Care More About Color Accuracy Than Speed (Me, The Reason My Main Display Is An S-IPS) Im A Gamer But I Hate Inaccurate Colors, You'd Be Suprised How Color Accuracy Makes Differance In Movies And Gaming.