I use to work for the company that made the LightSheer laser,
the alexandrite lasers that were being used at the time was the market that we were going to try and replace
alexandrite lasers leave you in lots of pain and are less effective,
Michelle Hayden is right,
training is critical, and often the places that use the lasers train the first person,
then that person shows the next one how to do it,
and years later after a few people they have no clue how to use it properly.
the other issue is people wanting to keep using older lasers to save money when there is way better technology out there.
the lightsheer will go up to 100 J/cm2 and if you have light colored skin that is how much you should be using on that laser (because it cools your skin off before zapping so they can get more energy in the skin without causing damage)
the people running them often are shy about turning it all the way up,
or if they do, they are sometimes not good at turning the power down when they start burning someone's skin...
or they let the optics get dirty and put tiny burn marks in the skin (if that happens they need to stop and clean it)
it really should be run right at the limit of what your skin type lets you run.