Alaskan chainsaw mills are designed for planking tree trunks and large logs that have a substantial mass and won't move on you as you make a cut. The "mill" is just a jig that keeps the chainsaw parallel to the top of the log. In that respect they are no more dangerous than any other chainsaw (says he, who has never used one). I believe that they will convert large amounts of timber into sawdust but they can be a cost effective way of planking logs compared with hiring a bandsaw mill. I got a Lee Valley catalogue recently and they have a couple of different sized Alaskan mills, prices starting under $200(US). I reckon if you have access to free logs it could pay for itself very quickly. Of course you do then have to store the planks for drying..a year for each inch of thickness, so you do need the space and the patience.