Besides the fact that the LED displays have richer colors than the LCD, the graphics were designed for a DMD, and the LED displays have the exact same dot configuration. In most cases LED is the way to go, unless you prefer one of the special rendering modes.
Quoted from thall17:
I would purchase another LCD as I think the LED are just too bright...
Most DMDs have plexi installed in front, pretty easy to swap in another color to dim it a bit.