So I got one pair of these and wore them yesterday for the first time. Out of the 6 people I encountered yesterday, 3 of them complemented my pants. They are awesome. The material is so lightweight and perfect for layering any other kyodan pant. It's so thin that I felt they might be see through but I did the squat test and the boyfriend said they are solid! Amazing! The camo print is rich quality. Love these.
I can't speak to the insulating abilities, as I got them after our cold weather ended, but they are definitely soft and comfy. They aren't thick, but I think they would be too warm for the gym? At least my current gym anyways, maybe your gym is like an unheated CrossFit garage or something. The design of the waistband does give "long john" but with a long shirt you can't tell.
I also wish they had more colours and prints. The Christmas/winter prints are cute but I went with the camo print, even though I'm not a camo person, just so I can wear them past the Christmas season.
I own two pairs of these and I absolutely LOVE them!!! I wish there was more of a variety of colors and patterns. I wear them to the gym and also as a base layer for winter sports, and they are amazing.