While I don't do a lot of mud... I have little doubt it will handle well with plenty of power. As to reliabiity... all I can say is the machine builds confidence with time. And contrary to what others might say, I love the IRS.I am interested in buying an '07 Rincon. If you have a stock machine, or close to please respond with any problems you have encountered. I plan on only adding a winch, heated grips and 26" mud light radials and maybe a box seat to carry stuff. I ride mostly hard pack, with or without water and some muskeg. Have come across some snotty stuff and am worried that the Rincon will get stuck. I currently own an '04 450 ES with over 4000kms on it and no problems. I am leery of the tranny and wonder of there is enough torque to get through the mud. The only reason I am thinking of trading in the 450 is for the comfort level, it does get tyring to ride all day, go mostly 6-8 hours at a time.