I know two guys that used them. Both said they thought it worked well, both shot a nice bulls out of them. Each tried them for two years and then bagged it, even though they had success using them.

The benefits of being mobile outweighed any advantage they gained from being in the treestand for each of them, and they lived very far from their hunting areas so had to pack it in and out every time they left or returned to their hunting area.

They both put them up in the corridor between night time grazing areas and daytime bedding areas. They sat in the tree stand and blew their cow call once or twice every half hour and used cow scent below them around the tree.
Both called lone bulls right to their tree just before dark (in different areas on different hunts).
I remember well how much fun it was packing those bulls out in the dark through the deadfall. That is when a GPS would pay for itself, unfortunately we did not have one.