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!
I have these in yellow (shoulder length), blue (double shoulder length), and grey (quadruple shoulder length). They seem to be thinner and stronger than other brands (10mm and 22kn). They are also very inexpensive.