I just sunk one of these anchors into varied soil - starting organic mush on top with clay and gravel then occasional rocks. I used 1/2" iron pipe and a standard fence post pounder for driving. It seemed secure as it went in smoothly- although with significant refusal after 3' depth. It was driven in a very brushy area (at the surface) with trees nearby. It was FAR superior to the helical disk type anchors - which I have also driven. These tended to hit a rock and stop depth advance abruptly. This reduces confidence in the pullout resistance. Also these helical type anchors need a circular swath of clear space in which to swing a lever to drive them down. This is not needed with arrowheads. Yet to be determined- the drawing for the arrowhead anchors shows they flatten perpendicular to the load as the load is applied -- meaning about a couple of inches of slack on the anchor line will appear. I will have to take this into account with either chain or turnbuckle(s) off this anchor to maintain even length & tension on the guy wires. Yet to verify pull test at 600lbs (the best I figure I can manage). I have high confidence this anchor will work though - I am impressed, and not easily so!