I use one sometimes, but VERY sparingly. I'll range trees, stumps, or other points of reference at the beginning of a hunt... but after that it never leaves the pack. Actually most of my stands are set in positions where I won't have any shots past 30 yards, and I can estimate yardage pretty close with just my eyes inside of 30. And I agree with what Drake said about the ARC technology... I think it's overrated, for most situations. In relatively-flat terrain or just slightly-sloping terrain, the difference in yardage will only be 1 or 2 yards, which isn't really even enough to change one's point of aim.
Example... If you're 20' off the ground, and the deer is standing 30 yards (or 90 feet) from the base of your tree on flat ground, the distance between your eyeballs and the deer is 92.2 feet. At 30 yds from the tree, that fancy ARC technology just corrected you for 0.73 yards. You think that's worth the extra cost? I don't.