I read the other reviews that mentioned issues with fit and decided to ignore them in the hopes that these shirts would work for me, but sadly the reviews were spot on. I'm between a medium and large in shirts and ordered and XL in the hopes of mitigating the snugger fit and because I've started to prefer looser clothing in general, but the XL feels like a snug L in other brands. Also, these shirts are indeed weirdly tight in the armpits, which is the main issue for me - it feels like someone is pulling upward on the shoulder seams and the shirt is being pulled into my pits. It was annoying for the thirty seconds I tried the shirt on, and I could imagine it becoming a big issue with extended wear. Also not very attractive as the fabric wrinkled weirdly in that area. Gave these 2 stars instead of 1 for the lovely fabric and colors (though FYI, the PNW color is much more of a forest green in person than on my screen, where it looked teal-ish), but the fit in the armpits is a dealbreaker. If Oiselle fixed this and either made them looser or offered an XXL, then they'd be awesome.