I've had a JD light duty bush hog for 16 years. Other than using some large batwing mowers to help a friend get his fields cut the JD is my sole experience with using a rotary cutter. But 16 years is a pretty long time.
There isn't much, in my opinion to differentiate one similarly spec'd rotary cutter and another other than longevity and durability. Deck. Gearbox. Blades.
Look at blade speed specs.
Anyway, all of this is to say that you cannot expect a machine to cut down trees _and_ mow your grass like a golf course. I have used mine for years to "mow the lawn" with the lawn being the fields around my cabin. If I cut it low, with the shoes pretty much on the ground, with high rpms and overlapping passes I can make it look okay (at best). Have worn my shoes out because of this. Mine does have chains on the back, which I like, but it still windrows to one side in deep grass.
I doubt a higher end similarly spec'd rotary cutter is going to be the answer. You might need two tools. After 16 years that is what finally dawned on me. I cut the true fields, rough stuff, roads and overgrown stuff with the rotary cutter and the "lawn" with a z-turn.