I almost bought an Advanced Laser Clinic franchise. I would recommend them. They make you go for 5 treatments to get the guarantee because that is what is really required to get rid of all the hair.
Hair has three stages of growth, and you must go get lasered during all 3 stages, and 2 times while the hair is in between stages (Total of 5 times). That is why it is not 100% when these places offer to do a 3 treatment program so they'll appear cheaper.
Also, the severe sunburn thing is a myth. THat will only happen if you go tanning before you go in for the treatment, which is something you shouldn't do. Go in for a consultation and they'll tell you all the things that you shouldn't do in order for everything to go smoothly. People used to get burned very badly when electrolysis was the method for hair removal. Your skin will be a little red but that's it.
It doesn't hurt that badly, it feels like getting popped by a little rubber band.
Works best on people with dark hair/light skin, but the technology is getting to where that won't be a problem.
*EDIT THe cost varies.. to do your back and shoulders $600-900 or so but whole body will be in the thousands.. mid thousands ($5-6,000)
Weigh this versus the cost of razors/wax and time savings forever and you have the answer as to whether it's worth it to you or not