Fits okay, the treatment that's supposed to inhibit bacterial growth doesn't work at all. I wore twice on two days to see if it this treatment would work. Not only did it not work, this is a very stinky shirt. I washed it according to instructions, dried it on low. It still stinks.
This is always an issue with backpacking base layers. Really cheap polyester works as a great base layer--so long as you don't mind smelling awful.
What really makes this shirt, well.... stink even worse,  is I also tried Merino wool base layer. They work like these are supposed to. Merino wool is quite a bit more expensive, but it works and it's pretty durable. (I have a hand me down that is at least 40 years old. It's finally too ratty, and it was always too small for me anyway.) You can wear Merino, get a bit stinky in it, let it air out a day or two and it's like it was washed. Nothing else works like that.