Looks awesome. Ask him if he can add a bottom and some foot stirrups, and a few pulleys. Then you could have the best of both worlds. Here's pic of mine. Works great for excercising, with the 2:1 pulley system, and I can put in anywhere in the room. The extra pulley also keeps all of the force directly against your feet, so there is no danger of it tipping over. The only problem, is that it's hard to get a good view of the limbs so close to the tree, so I usually videotape with my cell phone in a tripod behind my head. I stole the idea for this tree from Dubois.
And a furniture maker would probably be able to make it a lot nicer than my 2x4 abomination.