Man, you are really well stocked with bits! Looks like the PD35 is really heavy duty, too. I think I could get by with the medium duty PD25 if I go with Land Pride. I like the fact that their bits are 48", compared to Woods at 42". To go down four feet you'd need an extension. It's interesting that some of the brands offer an optional hydraulic cylinder for down pressure, but it sounds like if you keep the cutting teeth sharp it should go down through all but the very worst hardpan.
It sounds to me that the advantage of double flite bits is faster digging, so for occasional use maybe the single flite would be okay.
It sounds to me that the advantage of double flite bits is faster digging, so for occasional use maybe the single flite would be okay.