That's what I was afraid of. I have about a dozen fruit trees and attempted to use the backpack sprayer on them. Good grief my arms cramped up and about fell off from the pumping.
I switched to my Spray Doc and it was much better. I fill it, pump it up and spray half the tank before pumping it again. If they made something like that in a backpack model, I would probably buy it.
Yes, the brush appears to mostly multifora rose, tree saplings, and some honeysuckle .
I've got a Solo. I'm going to buy a Stihl pretty soon. The Stihl is much better made as far as I can see just from looking at it. The Solo is OK. Just too much plastic. Since I can use another one I won't be buying another Solo.