Well, I finished studying that knot pdf you posted and I must agree that the body rapel (I think that is what you are calling the hasty rapel) is preferrable. Seems that it is really easy to tell if you have the body rapel correct before you are swinging out over the edge and it is really easy to put the rope where you remember the rope burns from the last time. It might be a bit harder to remember this knot and as you pointed out one wrong twist in the tying and you are in free-fall with nothing to stop you. I also am interested in the issue with how hot that biner will get with different ropes. Body rapel is the first I learned and was actually preferred by my instructor as "perfectly adequate if you take your time and doesn't add to your gear weight. Don't know how many coats he went thru that way tho.... Seems this same fellow preferred down climbing rather than rapelling anyway.

I'm sure that the techniques preferred for mountaineering / climbing might be different than those preferred for rescue. There is a much greater urgency in the rescue and nowhere near the same passion for perfection of technique and love for the challenge. In rescue it is more important to get the victim out than to proove that you can handle a 20 foot overhang. When facing that sort of a challenge it is probably better in a rescue situation to rapel from the helo rather than to down-climb the overhang.