I ride in New England with a variety of surfaces most Hard pack roots and some loose gravel and sand.. I have had 4 runs on it now, and I got the matching 603 for the front as well. I am Novice intermediate rider on a 2005 WR450 (loads torque) – The front tire is WAY better than stock Dunlop -- The 604 hooks HARD, in hard pack but has be spinning like crazy in loose or soft trail cover.. 5th gear I was blasting the guy behind me, but I was still in front ;) – I did tear the side wall second run out which I have never done before not sure what caused it.. I would probably try a bit softer compound next time out.. If you are on ALL hard Pack I would say go for it, if you have a mix this is not the tire for you..