I can recomend API's hang on steps that use Lag bolts. Just screw the bolts into the tree, then hang the step on the bolt. You leave the bolt in the tree all the time, so you don't have to bother screwing and unscrewing steps. You can hang the steps on the bolts in no time and be hunting. 15 steps should be able to get you high enough for most situations.

TAKE YOUR KIDS HUNTING AND YOU WON'T BE HUNTING FOR YOUR KIDS