There is absolutely no comparison; the LEDs do such a much better job. Now, that said, simply upgrading to a halogen or Krypton bulb helps a great deal. On my 6v systems, I like to run a 4.8V Krypton bulb. "Overclocking" the bulb takes a good bit of life out of them, but I also get a lot more light. Some-- our own Forumite Minisystem-- have had good luck retrofitting LEDs into vintage shells. I tried it and my results were lousy: the reflectors weren't designed with a tiny bright point source shining only forward in mind.

Some of the folks at the Candlepower forums are getting better results, but I don't know any specifics.