If you guys wear a belt, hanging is a real issue. I have worn Seat of the Pants Harnesses, as have the rest in my teaching cadre and I have come out of stands in them, often, as has one instructor that had earlier had back surgery..
With a full body harness (at least the SoP) You hang upright, you can breath, you can move and you can get back on your steps or straddle the tree to shinny down. In a belt, you often end up upside down, your chest is constricted and you can't breath very well at all. About half the time I did this I could not "save myself" and needed help.
I don't sell SoP harnesses and don't recommend them over the others. You pick one and wear it. The difference between the belt, any belt, and a harness was very obvious to all the students that saw me perform.
Don't believe me, try it yourself. Do it from only 5 feet up and have help.... several guys you trust. You will likely need them if you use a belt.
ChuckC