I have a couple hundred acres and at times I likely severely over use my 5030. I have a fairly complete metal working shop and I made a 7' rotary cutter to where I can use it as a battering ram. It is completely boxed in with 3/8" wall 2X2 square tubing and has 2X3 3/8" angle every 14" across the top. I used 1/2" hardened wear plating on the bottom edges and on the leading edges. I do have a slip clutch to protect the gear box, but otherwise, if I can push it over with my loader, I'll chop it up. I got a nice sized rock this last time out and put it through the top of my cutter between my angle bracing. I don't think I really want to add any more steel to this thing, so I'll likely just beat that rip back down and weld it shut. I'd guess my brush cutter weighs in around 1200 pounds or more.
I have hills so steep that you cannot walk up them. I've run off the top of some using my FEL as additional stopping power and made sure that I hit all the bushes and small trees I could on the way down. The cutter is behind me chopping away as I go down. The only time I run short on power is when I bury it into the ground or drop off in a deep hole and have the cutter go under water. That bogs the engine down quite a bit. Otherwise, I've never had an issue handling a 7' rotary cutter.