No offence to anyone, but making a decision like that based on comments from someone who deosn't even own a PHD doesn't make much sense to me. 3 PT post hole diggers aren't that dangerous, and down pressure isn't going to be worth the cost of a hydraulic unit, IMO. As mentioned, when the auger stops digging, moving forwards or backwards a couple inches usually does the trick. Sometimes all the downforce in the world isn't going to make a difference. There is no safety difference between the two that I can imagine, and I really can't understand why so many people thing that PHDs are so dangerous. I would consider them one of the safer PTO attachments, as long as common sense is used. Stay on the tractor and there's very little chance for an accident. Again, I don't mean to offend anyone, but I'd hate to see someone scared into spending 4x the amount for no logical reason.