Ordered a pair of these pants for a long train trip (8 days, 7 nights), intending to sleep in them instead of regular pants. Just got them and tried them on: they're perfect! They have a very loose fit through the seat and upper legs, the waist is very loose as well, and the legs are quite a bit longer than regular daywear. All qualities I was looking for, for a pair of quasi-pajama bottoms that are suitable for public travel. I am short and chunky, so I ordered a 3x. The fit around my tummy is just right, plus the crotch doesn't sag, something a lot of larger sizes do on my body shape. I usually prefer the waist to have a good elastic grip, which these pants don't (as other reviewers have commented), but upon reflection, that's a good thing when trying to sleep in regular clothing. You don't want tightness around your waist (or at least I don't, which is why I'm a nightgown type of person). And the longer leg length means they don't ride up as much, exposing your ankles/lower legs to coldness or drafts.
The material is very lightweight and fairly thin, but surprisingly, the pants feel pretty warm. Again, perfect for long distance travel, but wouldn't want to necessarily wear them outside and expect to stay warm in cold temps. I haven't washed this pair yet, so can't comment on how it holds up in the laundry, like pilling etc. As far as I can see, the seams all seem to be well-sewn, but reserving judgment till after the first few washings. All in all, I liked the first pair so much that I've already ordered another pair to take on this same train trip! Will update review if there's anything to add after the trip.