Another happy customer here. I had it done 4 years ago. I did armpits, lower legs, bikini and neck. I have dark hair and light skin which works best with most lasers. There are some lasers that can do lighter hair. As for regrowth, if the treatment is done properly, the hair folicle dies and does not regrow. Your body though, is in a constant cycle of hair growth, so new hairs can grow in areas that have been treated. Since the end of my initial series (I think I had 5 sessions) I go back once a year and get any stray/new hairs zapped. It is expense. Check prices at several places. My daughter checked into it awhile back and each time we baulked at a price at this one place, they came down as if she was buying a used car. Some places will have specials like buy 1 treament area, get the second for 1/2 off. Some have guarantees that vary from 2 years or longer. For me it was well worth the money and my DH will agree. I had very course hair and he is extremely happy that he doesn't have to sleep with a porcupine any more (even though I shaved everyday, I would have five o'clock shadow LOL). I still have some light fine hair that I sometimes shave just to have a really smooth look, but it is so fine that is it not noticeable.
It can be uncomfortable. I did not have any problems with burns, but one session I did have a reaction to the chemical that cools the skin with each pulse. Had to take some Benadryl and use cortizone cream to relieve the itch. Also be careful if using a pain reducing cream before the session. Some places recommend you use the cream and wrap the area in plastic wrap. There has been at least 1 reported death of a girl whose body absorbed too much of the lidocaine type product and died due to the reaction.
Hope that helps.