I've found that a well-built trail runner, with pronation control and stability control, provides far better ankle support than any heavier boots I've tried. The problem is that boots support the ankle front and back but don't resist sideways ankle-turning. It's a solid footbed that does that. I resisted going to trail runners for years until I found out that I couldn't turn my ankles in mine no matter how hard I tried. That is not true of my 48 oz. per pair boots, in which I've turned (although, fortunately, not sprained) my ankles numerous times! I took ankle braces along on my first few trips last summer just in case, but never needed them. I've been hiking in my boots this winter and find that I have to watch my step a lot more carefully than in the trail runners.

Admittedly, I only do easy cross-country stuff, and stay out of scree for the sake of my dog. It's nice to have some kind of ankle protection when you're in scree! But some of the trails I've been on with the trail runners were steep, rough and rocky to the point of having to use my hands now and then. Here in the NW we have lots of really rough hiker-only trails and many regard the PCT as "Interstate 2000," fit only for wimps. Admittedly, at my age, the PCT is just about my style!

In the end, it's whatever fits, supports your foot and is comfortable, which only you can decide--everyone's feet are different! I tried a pair of Keen mids and found no foot or ankle support at all. Your Mileage WILL Vary!

Montrail has just come out with a model called "AT Plus" which their customer service tells me is "just like the old Hardrock." I can't confirm this because they are not available for sale yet. There will be a high-top version. If it has the support features of the old Hardrock and otherwise fits you, that might be ideal for what you want. This is pure speculation, though!