Based on other reviews, I ordered a size larger than I wear, and it's still a half size to a size too small.  So I would say order 2 sizes up.  It's also not 100% cotton, but a cotton/poly blend.  That means I can't wear it for some uses, and it's not as comfortable as an all cotton shirt.  The material is ok, kinda thin, and the sewing seems fine. I like the color.

Summary - if you don't mind a blend, a little light weight, and order a couple sizes up it's a decent shirt.