(e:Drew) said the barrels were safer and I argued that surely one could break their neck or other bones in the course of the fall if inside a barrel. (e:Drew) countered that people could be packed in the barrels and I imagined curling up inside a barrel and having styrofoam peanuts stuffed in around me so I wouldn't bump around and break.
So today I found a link that explains the different daredevils who have barreled over the falls and the techniques/equipment they used and the results. I think the most interesting barrel story is the guy in a barrel who survived the fall, but the barrel was trapped behind the falls for 14 hours where no one could reach him and he died from suffocation:

Isn't life hard enough that you have to go and die suffocated behind the Niagara Falls? Loco.
I won't use the term miracle that he lived (I read it last night also) but the odds of it are pretty small, that water most have been pretty tough to stand down there. In terms of the best way to go over the falls, I think it all depends on what kind of barrel you use it also changes based on if you go over the American side and down onto the rocks or if you go over the horse shoe falls. I'll go with the crazy answer you have to go over in a boat that can go faster then the water so that you fly past the falls and then fall. On a side note I wonder how he guy had his clothes ripped off but he stayed above water?
There's a bunch of musemums near the falls with cool artifacts too that you should check out!
That is pretty miraculous. Spending 40 minutes in water that cold would be ordeal enough.