Bought these for the 100 mile Haute Route AT traverse from Chamonix to Zermatt -- they are fantastic!

Softshell fabric upper leg is much more abrasion resistant, breathable, and the cut fits better than Patagonia's comparable Backcountry Guide Pant. Side leg vents open all the way for maximum cooling when skinning uphill (Patagonia Backcountry Guide Pant with fabric mesh in the leg vents only opens 2 inches max, not cool). With side vents zipped up on the downhill, over a mid-weight base layer, the Trailbreakers completely cut the wind and keep your legs warm even in high winds, or when you're sweated up.

The 5 zippered pockets are terrific, easy to reach, just the right size, so they let you keep all your essentials (passport, snack bars, knife, cash, etc.) in the pants so they never get misplaced when constantly shedding or adding top layers as you heat up on the climb then chill on the descent. Knees and lower leg have a snowproof, waterproof breathable shell, and the removable internal gaiters fit perfectly over my AT ski boots. I'm 6'1", 160 lbs, 32" waist, 34" inseam, the Medium size fit was perfect over a power stretch base layer.

After living in these pants for nine days of continuous ski touring,from valley altitudes and temperatures to 12,500 ft., all snow and weather conditions, plus travel to/from the mountains -- they did it all -- a phenomenal AT pant from OR!

Comments about Outdoor Research M's TrailBreaker Pants!":

Let me begin by saying every other OR product I have owned has met or exceeded my expectations but the Trailbreaker pants fall short. These pants have several features I appreciate, for example, the side vents, large burly scuff guards, built in gaiters with rivets for cordage, and the waterproof lower legs. I have used these pants winter climbing, touring, front country skiing, and while working in a winter mountain environment. My only complaint is the upper soft shell material seems to be degrading very quickly. I has begun to become very "fuzzy" with small fuzz balls of material on the surface giving it a textured appearance. Aesthetics aside, snow tends to adhere to the textured surface and melts from body heat saturating the material. I also own the Contour and Exos pants and both seem to be made from more durable soft shell materials. OR may be experimenting with a new material for the Trailbreaker - if this is the case I would reconsider.

Comments about Outdoor Research M's TrailBreaker Pants!":

The combination of breathable material up high and more waterproof material down low is genius. Lots of pockets (probably more than you need) and a specific beacon pocket with attachment point- awesome. Very comfortable. By far the best ski specific soft shells I've seen.
One gripe so far: The vent zippers open downwards and have a tendency to open on their own. It would be nice to have the zipper-pulls placed together (as opposed to one on top and one on the bottom), then you could choose if you want to have them at the top bottom of the vent.
Also, a small tab on the gaiter so you can easily pull them away from your boot and get your gloved hand under them to access buckles would be nice.