I've had this harness for about a year now and have used it for gym, sport and trad. I love the fixed leg loops, and how packable the harness is. It packs up into a tiny burrito size and is easy to take with me on any approach.
It's very low-profile while climbing and doesn't feel like a thick diaper like some harnesses.
I would wear this harness for anything except hanging belays. While reading reviews, I never read anyone complain about hanging belays, but this harness pinches the outside of my hips and my leg goes numb. Maybe it's just me. I'm currently looking for a burlier harness for hanging belays, sacrificing packability.
In short: It's sexy, ultra compact and convenient, extremely low profile, and good for all activities besides hanging belays. I'm 5'11, 160 lbs, 31 waist, and I have a size medium harness.
Extra star because while at the gym someone stole my harness stuff sack (which seriously depressed me because it packs the harness so small) but when I called Arcteryx, they offered to ship me one for free. I'm a stickler for great customer service. Thanks Arcteryx!