Starting and stopping at Two Wheels of Suches, a famed motorcycle campground in Suches GA, this route is a easy-medium difficulty for big bikes... a step above simple gravel roads with some nice unmaintained forest service roads, some good mud (depending on weather) and some pretty big water crossings. There is also some pretty good curvy asphalt between the gravel and some trails off the northern section. Nothing a big bike can't handle, but can easily take all day, especially with some side-trail exploring.
Most of the dirt in this route is gravel roads, some rougher than others but pretty easy. On the north end of the loop (Upper Hightower Rd & Charlies Creek) is where the difficulty steps up a bit. You will get into some Jeep trails, good water crossings, and unmaintained two-tracks. Fun stuff with a creek crossing that is about 40-60 yards across. Off to the side on these two roads there are some trails that are fun and can get pretty rough and muddy.