Since nobody else is replying with actual experience, I'll tell you what I've found doing my research (which included reading other people's experiences).
Electrolysis shouldn't cause scars if done correctly. Of course, there are people out there doing it who aren't properly trained and don't know what they're doing, but look for a reputable place and you'll be fine. They will know how to adjust the strength to be the most effective without hurting too much and without harming your skin. Ask for recommendations from people in your area, check reviews online, and if you hear a popping noise when they zap the hairs, walk out the door immediately.
Now, even if it doesn't leave any marks on your skin, electrolysis is likely to hurt more than laser, and it's slower (because it's done hair by hair as opposed to every square centimeter), so that may be a factor when deciding. It's also the only thing that will work if you don't have dark hair and light skin.
