The cut is easy if you can follow the line, I use a little tree trimmer chainsaw that I find most controllable for me.
The bigger the log, the shallower the cut, the thicker the wall.
You get just a fraction over 1R per inch with softwood logs for insulation value.
My building of log structures has been limited to NW Montana and Alaska where sub-zero winter winds blow and log homes are cold and have proven to be rather inefficient.