Replying to Jiberish LoHi sizing help please

I'm interesting in buying a LoHi sweater for mostly wearing around casually, not so much for skiing. I'm 5'11" with a normal build and was considering buying a medium as its length should be 29-29.5" which is fairly large (I believe). I'd prefer to not look like I'm wearing a dress on campus, although I've been debating between medium and large. I've never purchased anything Jiberish before so I was hoping people could provide any input, it would be appreciated.

for those saying gear talk, I know, but i was hoping for quick responses and gear talk isn't frequented quite as much, so i'll go ahead and start with an inb4 gear talk to get it over with