What are the negative and positive aspects of laser spine surgery?

Uncertain. Most spine surgeries have risks and benefits, most often based upon peer reviewed literature. Most facilities that offer these "laser" procedures should discuss such risks. As a reconstructive spinal surgeon, I have seen patients treated in these facilities who report acceptable pain relief. I have also performed major revision surgery for bad outcomes from laser surgery.
Varies. The laser is simply a tool used in spinal surgery and does not fully describe the full nature of the spinal surgery itself. The laser itself can be used to shrink and coagulate soft tissues such as disc herniations aiding in their removal. You would definitely want all your questions answered by your surgeon and don't hesitate to get a second opinion. Thank you for your question.
Depends who does it. That depends on who does it & for what indications. It is definitely overused. Most issues that have been operated on this way tend to not even need surgery & would have gotten better non operatively. Be wary of anyone who's says it is of little risk as there is always risk and it may be of little benefit. For certain tumor surgeries, there is an indication.& in minimally invasive cases.