The blade is ridiculously bright and lights up in an instant, the handle is gorgeous and beautifully constructed, I mean, everything about this lightsaber is just perfect. Even Luke Skywalker would be drooling over this. Watch it light up:
The Return of the Jedi lightsaber was made by Bradley Lewis and he documented his entire process over at Slothfurnace. Follow every step of the way, from pre-planning, to cutting, to wiring the lights and testing. It's a truly remarkable piece of work.
Here's the finished lightsaber (without the detachable blade):
And a few shots of the building process: