Sherpa Benetwrote a review of Arc'teryx Phase SL Boxer - Men's on November 10, 2014
Familiarity: I've put it through the wringer
Fit: True to size
Are these expensive? Yup. Do they lack a flyhole? Yup. Do they chafe? Nope. And that's the most important thing when you're out on the trail. Arc'Teryx has made these ultralight, yet surprisingly durable. The seams are well-stitched, and well-placed. The fabric is smooth on the inside and out to prevent friction. As an added feature, these breathe better and wick moisture better than other poly-weaves; phasic fabric doesn't just feel nice: it's superior. Add in silver-ions to fight stank and funk and you have some great skivvies here. I've used my first pair consistently in rotation for 6 months, and have decided they're great enough to purchase a second pair.
For fit: I'm 5'9", 160 lbs with a 30-32" waist and slim legs. Size small fits comfortably.