REI has created a really good pair of pants with the Airflyte. Almost perfect, in fact. The first great thing about them is how they look. They're neither baggy nor tight, with sufficient room in the thighs to accommodate actual muscle – something we frankly didn't expect from a running pant – and a nice taper in the legs. The overall effect is a neat, almost tailored look that transitions easily from trail to town.
What really matters of course is performance, and here the Airflyte is perfect for anything active in moderate to cold weather. The nylon/polyester/spandex blend has four-way stretch that lets you forget it's there, absolutely no binding or drag whatsoever, making them perfect for climbing or anything else with contortionist requirements. Use your imagination.
The material has just enough heft to it to provide a small amount of insulation, and strategically placed panels behind the knee and along the legs help you keep your cool when the going gets steep. The fit is a little large in the waist, but the flat drawstring dials in the fit and because it's elastic as well you can probably just leave it tied. The length is at the ankle, where it stays thanks to the stretch fabric: no riding up here, and bonus, they come in normal and short length to suit your preference.
There are no hand pockets, which we really appreciate on pants designed for movement. There is a small zipped lumbar pocket center-back, just big enough for credit cards. The only other feature are ankle zips to get them on over shoes, with reflective piping for visibility in low light. We're really searching for something to criticize about these pants, but they're even on sale at the moment so we got nothin'.