I too prefer the sling shot method, but it does give me the willies sometimes. Last year we were doing storm damage work in good size trees, some had the first branches well above 100'. You could get a 10oz up there, but not down again because the bark was spongey. Ended up tying a 16oz and a 10oz together after we got a couple lines hung up already. To get it up there, we added an extra 4' section, tunring the pole into a 12 footer. It was a two man effort... one guy would put his foot at the base of the pole while the other loaded and started retracting. As it got more retracted, you'd stand it up, and then take over holding the pouch while the other guy stabilised the pole. You get down on your knees and keep going, by now you've got 8 or 9 feet of stretch on that puppy and you're really flinching in fear for your life. You'd be killed for sure if something let go. You fire it off and it goes forever! And bumps the trunk about 2 feet short. So you do it again....
I've thought about using the 'behind the pole' method just for safety, and it's true that once in a while the line doesn't clear the forks using it the way I do. I've gotten too used to it though, and my aim is awful when I do it the other way.
Shaun