The hard ground is definitely the downfall to the pigtails. I have several different styles but my favorite for hard ground is the 3/8" round steel with an adjustable wedge clip that requires no tools. I took a head from a 2 lb. sledge and welded a 12" piece of 1" pipe to it and use it like a mini post pounder, works like a dream. The pigtails or even the plastic step in posts with a steel point are great for soft ground which I bet you don't have much of.