I bought two pairs of these pants for my husband for work. He's a professional gardener, so he needs pants that are durable enough to hold up to dirt, snags, and all sorts of rough use while also allowing him to have a good range of motion and flexibility. These pants seem like they will do the job. He has not worn them to work yet because it is the off season for him, but the material seems much more durable than his other work pants that kept ripping. As the person who has spent countless hours patching and repatching his work pants, sometimes on a weekly basis, extra durable fabric is a must, and the reinforced knees (mid-thigh to mid-calf) are a wonderful, added bonus (a gift to myself, really). He also was able to sit, bend, kneel, and squat comfortable in them. The legs and hip areas were loose enough for comfort and range of motion, while the waist (38) fit perfectly. I can't really comment on the fit of the waist compared to other pants because he has lost 25 lbs since we bought his last pair of pants in a different brand, so I had no idea what size he was when I ordered; I just bought a couple different sizes based on my best guess. They seemed a bit long when he first tried them on (he is 6' 3", and I ordered the 36" length, his normal pants length), but the length was perfect when he had his work boots on. For color, I bought one pair in black and the other in loden. They are both nice colors that seem perfect for hiding dirt stains. I have to return the loden because it is too big (size 40), but I will replace it with one in the same color.
UPDATE 4/11/2018: Since I left my first review, I have ordered four more pairs of these pants because they are so comfortable and durable. He now works on a landscaping crew that gets contracts fixing people' yards after the electric company has dug them up, so he's hauling a lot of dirt and often gets on his hands and knees installing sod. He also sometimes works with the tree crews to clean up brush, so his clothes are often getting snagged by tree branches and sticks as well. He only has six pairs of these pants, so each one has been worn about once a week (sometimes more) for over a year now, and they're barely showing wear. There are a some tiny spots on each pair where the fabric looks a tiny bit frayed or thinner than the surrounding fabric, but nothing worth getting my sewing machine out yet. Most of the spots are on the usual areas, like the hem or on the double knees (still my favorite feature). Some areas of the pants are a bit faded (knees, mostly), but that's the least of our concerns. He says the pants have been very comfortable in all aspects of his job, though they do get hot during the summer, but he figures he's going to be hot regardless while working in the sun. In the winter, he wears a pair of long underwear from Eddie Bauer underneath for extra warmth. As the person who does the laundry, I can also say that they come pretty clean from the wash as well, without much effort on my part. I use about 2/3-3/4 of a cap of laundry detergent (versus half a cap for a normal load), and I don't fill the washer up as much as I normally would. I do give them a pre-wash sometimes if they're literally caked in dried up mud, but that's it.
BTW, for those wondering about the "Dirt Drop Vents" on the double knees, when you're working in dirt on your knees, small dirt particles can work their way through the fabric and get trapped between the fabrics of the double knees, so it's good to have the small slit of fabric to get out any trapped particles. Just make sure to shake them out before washing, or else you end up with mulch and small twigs in the lint catcher of your dryer...