Dale, genius, my hero. Let me opine on how happy I am at the moment.
I just dug out the cheapo Black and Decker trimmer designed for small hedges in Seattle and cleared about a 15X15, not too overgrown section. This hedge trimmer is too wimpy to deal with big canes, but the ability to de-limb the canes without having to do it by hand with a lopper...total game changer. I'm more than happy to get in there with the big canes and lop them apart, but what a difference. I do have a metal blade for my weedwhacker, but I have found it far too scary to really commit to using. I'm a strong woman, but I find a gas-powered weedwhacker can drag me around with just the plastic twine...much less a metal blade.
I have about 1/3 of an acre of blackberries and my previous efforts to deal with them has invariably resulted in me seriously throwing out my back. So, the roots have to stay. Any proud owner of a himalayan blackberry patch knows it is about management, not winning. Having an easy way to knock them back over and over again is exactly what I need. They can stay forever in Zone 5 and let mother nature figure out how to deal with them, but I'll be dead before that happens, so I need a way to deal with them on the rest of the property. If my little, crappy trimmer can do this well, a more serious one might be in order down the road. My tool budget has been exhausted this year, so the little B&D and I are going to be out there doing what we can.