Do I need another anorak jacket? I do not. Do I love this anorak jacket?! I DO. It is oversized but in the best way. I am in the medium and yes, it fits very oversized. If you want a more tailored anorak this one is probably not for you. But if you like an oversized look, this one is so nice and relaxed! The quality is nice, too.
I would say size down if you don’t want an exaggerated oversized fit. For me the medium is perfectly oversized.
I’m in the medium of the shirt, I’m in the 30 of the jeans.