Not being a livestock type, never realized how many horse lovers there are out there who take great pride in their draft animals and doing the job properly. These operators also seem to really care about the environment and future tree inventories. One of our local megasawmills even pays a premium to horseloggers- mostly a PR thing, but certainly preferred by us locals over the mega clear cuts going on. Sure interesting to watch. Even had school classes out to see it.
Low impact has less to do with equipment, then on the method of harvesting.
Log length skidding will do less damage then tree length skidding. The ATV is attractive due to its low cost and compactness. But it doesn't have the necessary power to do a good job, and may cause more damage then needed. They also make a diesel ATV that has much more torque than the conventional gas jobs. More costly to buy.