Has anyone replaced the seat on their G650GS? I bought mine (2011) in the fall last year, and am finally getting into gear riding to work every day with it and boy, does my lower back hurt. Not kidneys but a spot right in the center of my lower back. Very painful when I get home from my ride so have to ice my back! Love my bike but need to do something about this. Has anyone tried after-market seats from Wunderlich or Corbin etc? How have you found them and while I know it's partly personal pref, has made a big difference compared to the cost of the seats? My commute is 40-50 minutes each way and right now having a hard time imagining a day long ride...