The stumps are the issue, it is the sprouts off the stump, but seeing/reading this made sense to those of us that have been battling the plant removal. It makes a lot of sense. Also states that it takes about 2-3 years for any stump over 8 yrs old to disintegrate, which I find about right as well. THe older it is, the longer it takes.
I bought a couple of the tools from the guy I have been on the fence, but now that I am really going to be wanting to carve out new areas I really felt the need to get this item and try it out. If it works, then i will suggest it on you, but I need to try it first.