I avoid boots as much as I can. Trail runners have done away with turned ankles, bruised ankles, and bashed toes for me. I do more miles in more comfort with them. And I never bother with Goretex for three season shoes, and keep my feet drier and with fewer blisters. The only blisters I get are due to foot fungus, which gets really bad in winter when I wear insulated goretex boots. So I am spending the spring season fighting it off so I can get back to breathable, comfortable hiking shoes.

Support comes from the sole of the shoe or boot, which is supposed to protect you. I have tried trail runners that were far too flexible and had sore feet. A good shoe will let you (if you have hiked enough to develop your foot's tolerance to the pounding and friction - this is the other half of the equation) go for long distances without extreme soreness or blisters.

Some shoes that have worked for me, same exact model and brand, have been reported by others I've hiked with to have blown apart almost immediately. Any shoe made in huge volume by a big brand will have a bad pair once in a while. This is why there are warrantees.

I have leather boots I only wear in shoulder season cold conditions while bushwhacking, and full length winter boots that I can hike or snowshoe in, but rarely do. Neither is ideal. I love trail runners.