Some how they made a super light harness that is still super comfy. My only complaint the rear straps are not easily removable.

I tore some gear loops off my old BD harness in a ledge dive last month, so I finally had an excuse to splurge and get this baby. Sweetest harness ever - if she could cook, I would marry her. Amazingly comfortable for hanging belays, compresses to the size of a baseball for packing, easy-buckle system for fast adjustment...pretty much just the best alpine big-wall (or all-around) harness out there. Yeah, you pay for it, but I guarantee you won't regret it.

Just a side note - as is typical of Arcteryx, the sizing is a little big (I'm size 32 waist and the medium is just barely SMALL enough for me) so make sure you try it on before you buy it or are able to return it for a different size if it doesn't fit.

SWEET!!!!! fits true to size,lightweight, extremely comfy, the only downside is the price

i bought it more as a novelty and figured I'd still use my BD and Petzl harnesses for climbing...but I was wrong...this always gets packed into my gear bag when readying and i love it...you'll forget you have it on until you fall...

Hey Arc'teryx, make the gear loops more rigid (stick out) like BD's Chaos please. Only folly of the harness, but other benefits outweigh even when trying to clip/unclip a piece of gear from one of the loops. Even in OWs a flatter gear loop isn't a massive advantage...

very light, wore it on top of 3 layers and 60 pound pack, didnt even feel that it was on me. very strong and comfortable

the harness is wicked comfortable, despite the lack of padding. love the light weight and packability. had to exchange for a different size, as it ran a bit small (i have a 30 waist, and the medium was too small). only problem i have was when stepping up to the large size, the leg loops aren't as tight as i would like them to be. should be great with ice. BTW, BD ice clippers fit the harness perfectly. thanks backcountry. as usual, customer service was excellent.

So far I'm completely happy with this harness, with no expectations of future disappointment. I do a lot of sport climbing currently and I've never been able to hold more draws on a single gear loop. put it on and forget. for me the adjustable leg loops were a must. I bought the 320 but the leg loops were entirely too small at the mediums size. so upgraded to this. definitely recommend it for any sport/trab/ice climbing

Not even a contest, the best harness on the market. Amazingly comfortably even at hanging belays and so light you tend to forget it's on. Packs down super small and the buckles are quick to adjust and bomber. Reversible gear loops and ice clippers are perfect. Only two small complaints. First, the haul loop is pretty weak but just slide an open loop of dyneema around the waist and you're set. Secondly, the drop seat is impossible to use so I switched the little Arcteryx buckle with one from a Mammut harness and its perfect. As far a sizing goes, need to try it on or be able to return it. I'm 140lb and 31in waist and got a Med. The leg loops are perfect but the waist is just barely small enough to fit. Pricey, but you get what you pay for!

I've been climbing in the X350a all summer, and I love it. No more having to double check that I'm doubled back thanks to the new buckle system. Hanging in the harness is quite comfortable too. (Not that I ever "take" or anything....) Draws and gear hang where I need them to and it fits like a glove. I wear size 30 carharts, and I went with the small. There's still plenty of room in the harness should I need to layer up in the fall or winter. This is my go to harness when there is a fall potential. When ski-mountaineering, or for a just in case harness, check out the Camp Alp 95:

http://www.backcountry.com/outdoorgear/CAMP-USA-ALP-95-Climbing-Harness/CMP0028M.html

This Harness is amazing. I am not the biggest fan as far as for trad climbing, or big wall, only because it dosent hold all my gear as well, and i have to majorly shoulder strap it up. But I can not say how perfect it is for everything else. I love the comfort when I am belaying my beginner friends, I can teach climbing all day with no complaints in this baby!
And then climbing in it is magical. I climb faster and longer all b/c of this harness.
I would def recommend it!