What it does well
Standing brush, saplings and stems within its rated size, processed in place, in one pass, with the material left as a mat that suppresses some regrowth and returns organic matter to the soil. On suitable ground it does this without the soil disturbance that conventional clearing and burning involve.
It is also selective in a way a dozer is not. An operator can work around retained trees, features and wet areas, which is why it suits habitat, trail and pasture work.
What it does not do
- Remove stumps or roots — the head works above ground
- Move or grade soil — that is excavation, and a different machine
- Correct drainage — a ditch, a culvert or a swale is separate work
- Handle stems above its rated size — those are felled and processed differently, or left
- Deal reliably with old wire, stone walls, buried foundations or debris — those damage the head
- Produce a mowable lawn — that is grading and seeding after the clearing
- Eliminate invasive species — cutting is a step, not a solution, for species that resprout or spread from fragments
The stem-size question, which is where quotes go wrong
Every head has a practical maximum stem size, and the useful number is not the largest stem it can eventually chew through but the largest it can process at a rate that makes the job economic. A stand that is mostly within that size and occasionally over it is a normal job; a stand where a significant share is over it is a felling job with mulching afterwards.
This is worth measuring rather than estimating, because the difference between the two is the difference between two prices.
What to ask before the machine is booked
Ask what the rated stem size is and what happens to anything over it. Ask what happens if wire or stone is found. Ask what the mulch depth will be and whether that suits what the land is for. Ask explicitly whether stumps are in scope, because that single question resolves a large share of later disagreements.