I have one, and I use it. The doe I shot on Friday was shot out of this.
I used to have a similar device called an Anderson Tree Sling which I lost a few years ago. The Anderson was much better as far as manueverability but the tree suit is a little more comfortable for the long term. I mostly use lockon stands but the tree suit is so quiet and quick to setup that I like to use it in areas where the deer are going to be close to my setup when I get in the stand. It may not be for everyone but I like mine.