I owned one and played around with it in tree's on my property but I never hunted out of it.I intended to use it to get up in the air quickly while rifle hunting.Packing it with a 7 or 8 tree steps.I never found it to be comfortable or particulary quick to set up.I sold it.
Preparing trees and getting steps in them is something I do a lot of and will continue to.I like going in to a stand and going right up the tree,with little to no noise or disturbance.I can see packing in a 6 to 7 pound tree stand for remote locations that I have set up previously and didn't want to leave a stand.I really prefer sitting on a seat and having something solid to stand on.
This was my experience,there are lots of folks who have excellent experience with them.John Eberhardt for one uses them exclusively.