I have no experience with a mulcher on an excavator. I do think they would be slower than a track mulcher. Maybe someone will jump in with experience on one. I agree, you really should look at renting if you have small acreage. If you don't have the right setup on your machine, you can tear it up in a hurry with a mulcher. Most of my experience is on a dedicated, steel-track mulcher, mostly a Fecon, FTX140, and some on a Rayco 100 and on the Kubota 95-2. The Fecon could do 3 acres/day, in medium to heavy brush and trees. It was excellent on stuff up to about 8". Capable, but not fast on bigger trees. On these type machines, it is all about the HP to the hyd head. I would lease a machine with a minimum of about 100HP, and then don't get in a hurry.