I have a BX22 and have been pleasantly surprised at the amount of work I've been able to do with it...once I got over the "go slow and baby it" phase. At this point, I'm not afraid to horse it around and it's done some impressive work, not just with digging, but for things like moving large limestone boulders around using a combination of bucket curl and other movements. Not "fast" work, but effective, nonetheless. I've also removed some fairly large stumps with the machine.
We have a heavy clay soil inundated with limestone rocks of variable size. When you get into the harder stuff, digging slows, but good technique gets the job done. I agree with the poster up above that there may be good value in some aftermarket attachments from places like Bro-Tek (
Bro-Tek: Tractor Add Ons) to help break up difficult soils, etc. I'm considering the thumb at the least for some of the heavier landscaping work I now am faced with since our addition was completed. I may also opt for their skid plates, especially since I'm selling my MMM after buying a ZTR for mowing duty.
As to the cost...yea, not inexpensive to buy one of these big orange power tools. But when you take the cost over time and consider the cumulative rental cost and time lost locating, transporting and returning a rental, things smooth out. You can add to that consideration the potential cost of hiring out the work, etc. For us, having our own machine has paid for itself several times over I'm quite sure.