"I also have a Bosch rotary hammer, an SDS-Max, that I have rod drivers for. It will sink a 1/2" rod in about 15 seconds in most soil, and has never taken over a minute, no matter how firm the terra firma."
What are the "rod drivers" and where do you get them? (or, are they a "home-made" thing?)
Just purchased the new Makita LXT400 18-Volt Lithium-Ion set from the Home Depot and I must say I am VERY impressed. Great power, light and easy to hold. Highly recommended if they do what you are looking for.
Renosteinke, they used to carry them on Oahu at a tool place called FKS, but don't anymore. It is too bad cause I would love to get me another brand new one.