…is like fear of the dark. Really. I'm afraid of the dark. Sorry, I digress again.
I'm not an experienced hiker, probably less than 200 miles in the last 3 years, but have spent quite a bit of time off trail, in crappy brush, since I was a kid. In my experience, the light weight hiking shoes work well even on trails with stretches of slippery roots and holes, craggy rocks, mud, and water. I did roll my ankles plenty of times from not paying attention, but no injury. My pack weight has been 35 – 45 lbs, and we hike 10-19 miles a day. (I used to sprain my ankles riding snowmobiles every winter, and in sports, so I don't have strong ankles) I wonder if the ability to roll and flex prevented an injury on the trail.
In the really wet, muddy, sloppy low trails everyones feet were wet, wether they had waterproof boots or not. My Sealskin socks came through great – just mildly damp feet, and I just turned them inside out at camp to air out.
Fit is more important, IMO – my toes were abused from sliding forward.
When off trail, in rough brush, I like the stick and junk protection around my ankle that a low boot provides, and that stuff would go under my gaiters the one time I tried them. (I hate stickers and sticks on my socks and in my shoes) I just purchased a pair of Golite boots, but expect to lace them so the tops are very loose and not providing any support on hikes.
YMMV