I fell on the opener of gun season in 2005. I was wearing a Summit S.O.P. harness and was hunting out of my Summit Cobra climber (open face design). It was 100% my fault. I was on too skinny of a tree that had slick bark. I did some sort of twist lean thing to shoot a doe. At the shot I was off balance enough that my bottom platform shifted and before I knew what happened, I was hanging some 20' above the ground.
Honestly, from there it is an adrenaline blur. I remember bear hugging the tree and reaching up with one hand and pulling down on my platform to get it to the point that I could get my left arm completely on it to use as leverage to pull myself up. I don't know how I did it but somehow I ended up back on the lower platform. After gathering my composure, I ran my climber to the ground, sat down at the base of the tree. I am man enough to admit that I was an emotional mess as the gravity of what could have happened came to a realization.
Overall I survived with simply some scrapes to one of my hands from swinging into the tree and a bunch of sore muscles. I didn't let myself hang long enough for the loss of blood flow to my legs be a problem. I retired that S.O.P. harness for a new one. My new S.O.P. has straps that tuck away that you can string under your feet to relieve the pressure on your legs and improve blood circulation should you need to hang for a long time waiting on help.
The guys are right, tie that safety rope as high as possible so your fall is a short as possible. Also, don't just rely on your harness and rope while in the stand. The most dangerous part is the climb and the transfer to the stand and back. Use a life line set up so that you are connected 100% of the time. I just had a buddy that fell the other day about 20' when he got near the top of his climbing sticks and the top climbing stick strap broke. Somehow he survived with no major injuries ... very lucky. A life line would have prevented such a fall.