I may never buy such a machine BUT I enjoyed watching this video, the technical explanations and the calm and composed demeanor of the presenter who does not appear like the typical schmuck salesperson!.. Good job with the machine and the presentation.I don't want the machine to bury the rocks to just have them pop up months or years down the road but I do want one that actually picks the rocks up and puts them into a container.I used to be a demonstrator for a turf company in the UK back in 1990 who had a Rotordarian franchise and this machine was their best seller. It's a fantastic machine if used correctly. As part of demonstration I would find rocks the size of your head and place them on the area I was working. It buried it with ease. Most of the sales came from race courses,golf course construction and farmers. Also the ground was NEVER pre-worked before a demonstration.