The main difference between Keen and the others is the fit. Keen fits people who have wide feet in the front and narrow heels. All the other boots, however fine they may be, give me blisters or corns on my little toe because their last is not the same as my foot. So I only wear Keen boots for hunting, backpacking, etc., now.
Of course, your foot is probably a different shape than mine is, so you have to experiment for yourself. But good fit is by far the most important thing, with everything else being a distant second.
This also includes so-called "custom made" boots, which don't fit my feet as well as Keen boots do. They should, but I have to assume they aren't quite as "custom made" as they would lead you to believe.