i've only done it on the scooter, towards the end of a long day out towards hidden canyon and the maze and stuff and i found it quite enjoyable, some semi-technical bits with some nice cliff-top views. seems to me there was a lot of rock. i don't remember if there was much sand or not, since sand is not really a problem on a dirtbike. i think the jeepers call it 'steelbender' or something like that.
mw