Executive summary: minimalist shoes will help you move faster and safer in technical terrain, but have a substantial transition period and come with several significant and perhaps irrevocable downsides.
Before preceding further we must define terms. Minimalist shoes can be broadly defined as those with well under 10mm of delta, and well under 20mm of padding at the thickest point. Technical terrain is walking where you have to, at least a little, always worry about each footfall lest injury result.
The idea behind minimalist shoes is that your feet and legs respond better to the stresses of hiking with minimal mediation between them and the terrain. If this is in fact the case, there is no reason why their benefits would not be even more significant in technical terrain.
My experience over the last three years has shown this to be the case. With minimalist footwear and the proper conditioning, I do tough trips faster and my feet and legs recover quicker. Rather than illuminate the endless and endlessly personal sub-merits of this approach, I’ll outline some of the reasons why it might not work for you.
First, your feet, legs, and core will need to proper strong for this to be safe. Wearing light and flexible shoes in savage terrain demands more from your body, especially connective tissue. This is not a strength which can won with a single, 3 month training plan, and looking cool with the right shoes is not cool if you strain your meniscus 10 hours from the nearest trail. If you currently use boots or heavy trail runners for this stuff, give yourself a few years to make the transition.
Second, you’ll be using different, much more delicate, techniques. M, above wearing Trail Gloves, is a good example. With mountain boots, the dreaded Glacier scree over rock-hard dirt can be sorted by kicking steps. With minimalist shoes, you’ll be smearing your way across on embedded rocks and minute weaknesses. Once your body gets there this is faster, but you’ll get slapped around along the journey to enlightenment.
Third, you won’t be able to use crampons. Microspikes work with the burlier minimalist shoes, like my X Countrys, but the KTS and K10 crampons are marginal and traditional flexible 10 point crampons are out. To get them to fit you’ll have to crush your feet, making them cold, and they’ll still try to rotate off your feet when you need them most. Obviously, kicking steps is out. For routes with ~2% steep snow I reckon the time cutting steps is more than made up for with speed on dirt, but at some point the amount of crampon use will reach a point that burlier shoes are wise. Very minimal shoes, like Trail Gloves, barely have enough structure to make Microspikes acceptable.
Fourth, your shoes will get thrashed. All minimalist trail shoes I’ve ever seen buy lightness with light fabrics, and 30 miles of off-trail beating may get you some good holes. Often aquaseal can keep the shoes alive for quite a while, but if setting off for a particularly long and rugged trek, light shoes may leave you stranded with a catastrophic shoe failure. This isn’t a necessary feature of these shoes, just a burden foisted upon us hikers by trail runners and their excessively manicured (getamountainbikeyabums) paths.
Go too far down this path and you may have the problem I have currently: I’ve become so accustomed to the efficiency of minimalist shoes that in spite of the expense, I rarely want to wear anything else. They just work too damn well. So be warned.