Electrolysis is better. It's pretty much guaranteed permanent. Might take a few zaps to kill a hair follicle, but it gets done. Lasers are currently permitted by the FDA to only claim long term hair removal, but there are girls around here that had it done 10 years ago and had no problems with regrowth.
I chose to start out on lasers because I've got the right combination of features: light skin and dark hair. If you're tan, or have light hair, or whatever, then the laser's not going to work as well. Not a problem for me, so I figured whatever I couldn't get with the laser I could clean up with electro.
The laser sessions ended up costing me a few thousand dollars. No joke. I've done seven sessions, and cleared most of my face. I started last year, in July. I would estimate I have about 10% of my beard left. I started going once a month, and now I go when I have enough growth to actually get my money's worth out of the session. However, the last few laser sessions haven't been doing much with the patches I've got left. I think I might be catching the hair at the wrong phase of the growth cycle.
So I decided to start electro to get at the hair I had left, rather than keep throwing money at the laser. Electro is cheaper per unit of time, but you can't clear as much. It might take a few hours to clear the remaining hair I have, where a laser could do it in less than 20 minutes. Electro also doesn't hurt as bad. The amount of laser energy is way higher than the electricity to kill a single follicle. Your skin absorbs most of that, and it feels like a sunburn. Electro leaves your skin a bit tender, possibly swollen, but that went away pretty fast.
Everyone reacts differently to both lasers and electro, so YMMV. My electrologist mentioned that age, coarseness of hair, and other factors can influence pain levels. Hair density is also a big factor. During my first laser session, my jawline hurt worse than my upper lip because the hair was so much more dense around my jaw. I think that clearing most of my beard with the laser sessions thinned the hair out enough that I looked less like raw hamburger and more like myself after my first electro session.
I have no idea whether my laser progress is going to be long-term (or permanent). So far the growth that was cleared hasn't come back, and it's been several months for some of it, so I'm hopeful.
The thing I really liked about doing laser is that it cleared my entire face the first time. It takes a few weeks for all the hairs to fall out, but that would have taken hours on electrolysis. Rapid progress, but high probability of regrowth. Electro is the opposite, slower progress but a much lower probability of regrowth. Depends on whether that's a good mix for you. If you're planning on full time soon, laser might be a good idea. If you have some time, electro will probably be a wiser investment because it's generally more effective.
If you're looking at lasers, lightsheer makes a good diode laser. It's important to verify what kind of laser you're going to be zapped with. Most of the stories I've read indicate that diode lasers are generally the most effective. Other types of lasers can be less effective. Test spots are always a good idea, but be prepared to pay for them, at least some of the time. Also make sure to give the test spot a few weeks for hair to fall out and to see how the hair grows back on it.
I hope that helps you out!