I don't know how serious your blackberry problem is, but I see you are also from Oregon. So you know that the blackberries can be monstrous. I clear them as a part time job (my archaeological grad student pay is not particularly munificent and I have been doing this kind of work for years anyway). I have used a lot of things for clearing brush and black berries, but if you are serious about clearing blackberries then there is only one tool for the job in my experience.
It's the Super Heavy Duty 2 Tooth Brush Cutter Blade. I can clear (and mulch as I go) more in an afternoon with that thing on a heavy duty weedwhacker than I could in weeks with a machete.
When I first started clearing blackberries by hand I used a sickle, then moved on to a machete. Eventually I sharpened a shovel and just used that. Then I was introduced to the two tooth and never looked back.
All that said, I like my machetes, but I've never used a 10 incher. I've always gone bigger, and I've never really paid attention to precise thickness. So I don't have good advice on that front.