Hi weasel squeezer, I had wondered about these and although I like the value of not banging a dead tree around I would rather use a Tirfor type winch with a kinetic recovery strap/rope. take up the tension gently and the kinetic rope would give the pull without shock. Rig up on one stump and only low down on the stem to fell so on the strongest part. The amount of jobs you would do like this is fairly small so the cost of a Koller is a fair bit since most of us have a Tirfor so only the cost of a kinetic rope , couple of hundred for a really good one, is much more recoverable. That said safety before cost so my comments in this case may be well off !!