I've been helping clear some brush lately. It's something that I've done since I was a kid around the family farm, so I have plenty of experience in how to cut the stuff. This time was unique for me, though. All of the tools used were ones I had custom made: an ax, a machete, and a Southeast Asian-style blunt-ended chopper (similar to the Rambo IV knife but better made than the officially liscensed product). The brush was pretty thick, a mix of mountain cedar, wild persimmon, some kind of whippy bushes that spread all over, and briars, narture's barbed wire. I spent a solid six hours working at it all by myself, and I covered more ground than I ever have before while clearing brush. I went through about three canteens of water and twice broke the ax handle because I overstruck.
I am really pleased with how my tools performed. They worked better than any of the commercially made axes or machetes that I've used for the same kind of task. Held good edges, and the ax survived accidentally splitting several good-sized rocks with minimal chipping to the edge.
Here's footage I shot afterwards. Not sure if it gives a good idea of how much area this entailed or not, but it was quite a bit for one man to do in less than a full day.