I hate greasing mine, just for the simple fact that if I don't wipe up all the excess grease, then dirt accumulates in it from the dust I ride in, so I grease it probably every 20 hrs, but thats NO MUD riding, all trails.
My buddys a farmer and he told me that when he was young he had an identical tractor to his brother and his brother left all the grease accumulate on the grease points on his tractor and he wiped his all clean. After 5-10 years and similar usage and hours, his brothers wear points were all worn out from the dirt working its way into the pivot points and his was tight as could be because he wiped all the excess grease off. So, I try to do a neat job greasing mine and it takes me forever to do it and wipe it clean, so I hate that job! lol