First off, one of my favorite trail runners is the Teva X-1 C (I can't decide between those and the Inov8 315). I like it because it's just right for my narrow heal, and the toe box is wide enough to fully accommodate the biomechanical spread of the forefoot without constriction; I've gone through plenty of brands that were just too narrow and pinched, even though the stated size was my size (D). Unfortunately, I don't think Teva makes this shoe any longer, so it's a good thing I bought a second pair!
My current favorite is the Saucony GridPro Outlaw, which I saw featured in Backpacker mag with glowing reviews. It's a mid using a "barefoot running" construction, i.e., there's only a 4mm differential between the heel and forefoot, yet it has a more than ample sole plate to guard against sharp rock bruising. In addition, it has an extra cuff that comes up the Achilies to keep out rocks and a D-ring at the bottom of the laces for attaching gaiters. I just completed a 24 mi traverse of the Crazy Mtns. wearing these, going over some of the steepest, rockiest, longest passes ever with nary a problem. It was like floating along in moccasins!
Also, any non-Goretex fabric shoe will admit some trail dust, but it feels soo goood to swish the ol' dogs around in a mountain stream that it's not a problem.
Lastly, the only time I sprained an ankle I was wearing high-top leather hikers, and I could always, always count on them to give me blisters...I haven't had a blister since I graduated to trail runners some 15 or so years ago.