I got one for DH years ago. He doesn't use it often (less often than he should -- he lets the weeds get too tall. It works better on young weeds) but when he does, he plays with his "flame thrower" with enthusiasm.
I have to close the back door to the patio (brick) to keep from getting smoke in the house.
He has been less enthused about it lately than he used to, because he says the weeds that grow back seem stronger and healthier. We wondered if it's the ash fertilizing them with the Forest Fire effect. But if you are diligent about it, my understanding is that it would kill off the existing weeds and keep down any new ones.
The patio really looks "cleared" after he's done, too.
Probably no need to tell YOU this Charlie, as you seem to be a careful person, but obviously, you want to remove any flammables from the vicinity and NOT use it during periods of drought.
Oh! Be sure to get the kind you seem to have spotted -- the one that attaches to the larger (like 5 gal size?) propane bottle and NOT the one that uses a dinky little 1~2L bottle sized one. At least the way *my* DH uses it, the little bottle would never be enough.