I was using the brush grubber this afternoon to yank out some bushes in our front yard, where we are re-planting with other stuff. For that I used the grubber and short chain attached to the chain hook on my 3-pt hitch log skidder plate, and plucked the shrub roots out by lifting the 3-pt hitch. Worked great and was very quick.
I think the main benefit to using the brush grubber is that it lets you yank out trees and brush by the roots without disturbing the rest of the ground around them. If that's not a concern, there are definitely other faster ways to get it done.
By the way, I wasn't suggesting using a long rope and pulley block with the brush grubber -- that would be nuts. I was saying that in the context of pulling down bigger trees, where the brush grubber isn't used. I agree it's not smart to pull down trees directly where it could fall on the tractor or operator. In those cases, a logging rope and pully block (to the base of another tree, can be a small one) lets you locate the tractor and operator out of the danger zone.