I've always had indoor/outdoor cats. I'm not sure how I would change that practice, really, because every cat I've had has wanted to be outdoors.

I haven't quite had your luck with it. In high school, the only cat I had got struck by a car. Since we've moved to the farm, we've lost three cats -- one to a snake bite, and two who simply didn't come back (I suspect coyotes, or fox, or some other wild critter).

Right now, we have one full-time outdoor cat who comes in only when it's cold, and one indoor/outdoor cat. They're both thriving. One of the reasons we keep cats is to help control the critter population, and they prowl far and wide (though thankfully not toward the road, which we are set back quite a distance from).

I guess it might be more responsible to keep them inside, where they would not be at risk from snake bite and other critters...but they would also be unhappy.

I dunno. I guess I think that as long as a cat is leading a healthy, happy life, then they should be left to be cats in whatever manner they choose.