I am now in possession of a 20W fiber laser. I can tell you they are very fun to play with 
The fiber I have was sold as a cell phone back glass remover, but it works as a standard fiber laser as well. It is nice being able to engrave on steel, aluminum, brass, and polymer plastics. Being a galvo scan head unit, it is incredibly fast to engrave items. I makes me want to get a CO2 galvo laser now. The only drawback is that the unit is only 20W, so engraving to any depth is a slow process, but surface marking, especially on anodized aluminum is blindingly fast. I can’t complain, my business partner gave it to me for free . It has a nice auto focus feature. A bonus is that it can still be used to remove cell phone back glasses, good money in that service.
