I wouldn't trade in for a B series, look at the L series or go to a Kioti or Mahindra. Kubota's are great (I have an L3200 and LOVE it) but I don't think the B series would give you a big enough jump to justify trading.
To answer your questions, I have been removing bushes from the ground with extreme prejudice with my ripper. I did about 300 feet over about 2 weeks. I have about 750 ft to go, and of course there are various trees and such mixed in with them. They are too close to a fence and row of pines to rent a dozer. Then I have about 45 dead ash trees in the yard that I'm going to have to cut down.
So anyway, I was thinking a larger tractor would be able to rip them out much quicker and save me a ton of time in general. But the reason I was thinking of trading both my units in, was because the larger tractors run $28k-$35k compared to when I bought my BX23 for $17k. I was just trying to reduce the payments as much as possible.
Too small? Everything is still cat1, right?