I have first hand experience in keeping some, removing some. IMHO It is great siding if you don't have to monkey with with it. My place is a hundred years old, and the siding guys went through pre sixties and the place was sided with it. In its' unmolested form it is fine. You can pressure wash it, prime and paint it and it looks good. If you dent it and break it, a minor break, you can caulk it. You can drill it with special bits, but the dust is toxically nasty.
The stuff of course is outlawed any more for manufacture. I have some walls that still have it and it is stable and sound. When doing a major remodel addition, I had to remove a sixty foot wall and dispose of it. I consulted the state regulations and contacted a couple hazmat removal outfits for quotes and information. One of the hazmat guys said if I chose to remove it myself, I could package it according to his instructions and he would accept it, do the paperwork and dispose of it for a really nominal fee.
I bought a half dozen used but like new fifty gallon drums with lids and rings, put all the stuff in them and labeled them with a marker and tag. I hauled them to his place and he took care of the rest. The real key to removal, I bought a new real good respirator and appropriate filter, and new goggles. I mowed the grass at the bottom of the wall real short and commenced removing the stuff. Each day I worked a couple hours and did an hour of clean up using a nail magnet and shop vac. You could put a plastic sheet down if you wanted. The shingles are real stable, the risk of exposure is when you break them up. That said, the real crap is the layer of dirt, dust and bugs underneath the layer when you remove them. Tools that made the job easier, wonder bar, sharp blades on my utility knife, nail belt, tight fitting clothes. Having my barrel right next to me facilitated a pretty effortless handling.
