555 is very twisty, but has poor sight lines, lots of blind hills, and the pavement is sketchy at best. Kind of like 536, it's worth riding once just to say you did, but there are more entertaining roads in the area. Also like 536, 555 has a high frequency of bikes going down. When I am down that way, I make a point to ride 550 and 377 (which both cross 555) and skip 555 entirely. Of course this is just my opinion. YMMV.