Thanks. that makes sense. Previously I have rented Hilti spline drive
rotary hammers. I had to drill a 2 inch hole and it was brutal. The
bit IMO, was in poor shape. One of the side carbide cutters was missing
and it was dull, if dull matters. I dont know too much about that.
How well should a 2 inch bit move thru concrete? 4 inches took me 30
minutes to drill.

I bought mine on EBAY, it is 1000 watt chinese drill and is much
better than I thought it would be.
it will do all 3 motions, hammer or turn or hammer and turn. and has
wheel to adjust the speed. Came with 3 drills and 2 chisels and an
adapter for a chuck.