Does this fit more tightly, like the Atom...
Does this fit more tightly, like the Atom MX, or more loosely, like the Gamma MX? I tried both and would like to go for a really snug fit, for trail running.
I normally have arcteryx size M and it fits me perfectly, but if it was cut like the Gamma MX I'd consider size S.
Looser than the Atom MX. I would say close to the Gamma MX. It fit nicely over a t shirt or base layer (I wear mediums as well). Watch out if you go to a small as it will be cut much shorter in the front.