Any tools with whirly parts, you have to be somewhat afraid of them. That is why when I make a saw sled, I put a bridge over the top of the saw blade, just high enough to allow whatever thickness of wood I am cutting to go thru easily. Usually that is 1/2" plywood, with the ocassonal piece of 3/4". This bride is wide enough I would have to lay my hand flat, and slide it under the bridge, to reach the blade. And that is not going to happen. I just have one extension cord I use for my power tools. So, when I finish with the saw for example, it is going to get unplugged. The worst injury I have ever sustained woodworking is when I stabbed my hand a little with a pocket knife. Fear of my router is why my masters are 1" thick, gives a lot of material to hold on to. Got no splitter, river, blade guard, on my saw, took all off when it was new. Oh yes, on my saw sleds, they have a hook on my end, so the saw blade will not get exposed after the cut, maybe a bit of overkill, but I go by the old saying, some is good, more is better, too much is just enough.
A sled that lets the bare blade come through the rear fence on the sled in inherently unsafe. I want a block of hardwood behind it to bury the blade in at the end of a cut. I think a lot of accidents occur when the workpiece suddenly slips forward and the user's hands follow so fast there's no time to get out of the way. Grrippers, push sticks and even simple 2x blocks help with a lot of that. I also suspect clothing, rings, bracelets, long sleeves are also involved with pulling the hand into the blade.
One of our members spoke of the Bosch, non destructive, fast blade drop that gives the protection without killing the blade. As I understand it, the lawsuit that stopped Bosch from licensing the device is over the flesh detection sensor. If SawStop's so interested in safety, why did they kill off Bosch in the USA? SawStop's equipment is very good, just way overpriced. I'd love to see the Bosch system available in most saws. I think SawStop's patents run out in a couple of years, after that, I bet Bosch will even the score by offering a very inexpensive license to include their non destructive technology in any brand that wants it. If they can do that for less that $300-$400 (retail), I think SawStop's day will be over...Save your fingers/wreck your blade and cartridge vs save your fingers, reset the blade...which is your preference?
Meanwhile, attention and a little pre planning and sleds and push blocks and sticks are the alternative. There may be two sides to every story, but once they hear the tale, most people then take one side or the other. Interesting how many have voted on this site.