Well I've always been impressed by it when it is adjusted properly. Having the e-brake lock the entire drive train pre-gear reduction is a powerful thing.
If you are all locked up you can drive right up a tree to the point of tipping over and set it and it will hold your truck there. Always a favorite at after wheeling party/camp sites with guys who aren't aware you can do that kind of thing. I have got a few guys to rip the steering boxes off their chevies trying to figure out how I did it. It's not for everybody but it is a vast improvement over the drum e-brakes for big tires.
I cut off the torsion bar brackets that hold the e-brake cable housing in place on the back end last time I built my truck so I need to address that with a new tab on the frame to get a good solid adjustment. The pads have always drug slack just a bit so I plan to do a tweak and tune this time to eliminate that.
When the pads get worn to a certain point you can't adjust it enough to work well, but it took me a decade and a half to wear them out to that point.
My only real complaint is the somewhat hard to source cushman brake pads it uses. I want to reverse engineer it for my boys' trucks but make it to use a dirt cheap and readily available brake pad.