The Arc'teryx Aerios FL Mid GTX is billed as a flexible footwear option for technical hikes. The FL of the name stands for 'fast and light' and these clock in at 370g / 13oz, while the 'Mid' suffix (which means different things to different brands) translates here as a cut that's somewhere between a shoe and a boot. In the same product line you'll also find a true walking shoe (the Aerios FL GTX shoe – the brand's best-selling shoe) and a much higher cut boot (the Aerios AR Mid GTX). So essentially, what Arc'teryx has chopped off a chunk of the ankle section to make a boot that's faster and lighter than the AR (All Round) version.
I tried a pair out at the Arc'teryx Academy in the Lake District, putting them through their paces on scrambling and hiking up mountainsides and through boggy ground, to see how they compare to the rest of today's best hiking boots for men or best men's walking shoes. (Because I have big feet, I was in the men's version, but there's also a women's fit – for more options there, check out our best women's hiking boots and best women's walking shoes.) Read on for my full Arc'teryx Aerios FL Mid GTX walking shoe review.
Arc'teryx Aerios FL Mid GTX review: design and features
The Arc'teryx Aerios FL Mid GTX are designed to be minimalist, high-performance and lightweight, allowing for speedy movement over technical terrain. The uppers are crafted from ballistic nylon with a GORE-TEX layer for breathable waterproofing, Vibram Megagrip outsole, and there's a pre-moulded EVA midsole for cushioning and integrated TPU shank for additional stiffness.
At RRP, a pair will set you back GBP £160 / USD $185 for both the men's and women's versions. Sizes run from UK 3.5 to 8.5 for women, and UK 6.5-12.5 for men, and there are three colour options for each. As you'd expect from Arc'teryx the design is pared-back, muted and very stylish – this is not a brand that's into garish colours or outlandish design flourishes.
Arc'teryx Aerios FL Mid GTX review: comfort and performance
Where these shoes/boots really shine is when it comes to flexibility – which is exactly what the brand is aiming for with its FL offerings. The sole is pleasingly responsive, with an effective lacing system delivering a snug, slip-free fit. This flexibility, combined with the Vibram Megagrip outsole, meant I could move confidently over rocky, uneven ground on my scrambling session, while the 5mm lugs also delivered good grip on softer, boggier ground.
The mid-rise cut offers slightly more support and protection than a true 'shoe', but is less restrictive than a traditional boot. In practice, there's great freedom of movement around your ankle, which is a benefit on certain types of tricky terrain and proved a great choice for the scrambling session I wore these for, although of course there are cases where a higher-cut and stiffer boot will be order of the day.
(I spoke to Arc'teryx product manager James Tomley, about what kinds of excursions this cut was designed for, and he has this to say: "This is hiking product, geared towards somebody who's enjoying their time on the trail, rather than off it... You want to be in terrain where you can see your feet, because if you're losing your feet down holes and stuff, it's generally good to have a bit more protection. [So] a hiking product geared towards people who are on the path as opposed to cutting new trails.")
Arc'teryx says the cuff around the heel is designed to seal out debris, but it's only partially successful in practice. The curve around the back of the ankle dips to around shoe-height, and I found water and dirt snuck its way in fairly easily. But that's the payoff you get from the more dynamic shape, to be honest.
Most of the upper is crafted from extra-tough nylon, which feels light, looks casual and is nice and breathable to wear, while toe bumpers and a reinforced heel offer some extra protection. As per the 'GTX' of the name, there's also a Gore-Tex liner – Arc'teryx has opted for the comfier, more breathable three-season version here.
A handful of other customers noted waterproofing issues in their reviews, but I didn't really have this problem. I wore them on a very wet hike, with a touch of wading through boggy ground ground thrown in for good measure. A little bit of water made its way in at points when the boot was submerged, but my socks were dry by end of the hike, so I'd count that as a win.
Another complaint that crops up a few times in other reviews is that this boot runs big. I found them true to size (although there can be a discrepancy between women's and men's fits, which sometimes confuses things for me in particular). For me, the cut for me was slightly narrow on the mid-foot (I don't have wide feet), making them a bit uncomfortable after a full day's wear. No other reviews complain of this, so I'd put it down to a personal fit issue.
Arc'teryx Aerios FL Mid GTX review: verdict
The Arc'teryx Aerios FL Mid GTX are breathable and lightweight, snug and ultra-flexible, and deliver great grip on a range of surfaces. The mid-height cut shines in situations where you need freedom of movement around your ankles, but for long days hiking I'd always opt for a boot proper rather than anything lower. There are a few question marks around exactly how waterproof these are, and although I didn't have any real issues, these are still probably at their best as a lighter weight, unrestrictive option for warmer weather excursions.