Arc'teryx Muira fit question

I was wondering how others sized this pack, I was thinking I was a Reg, size in the pack, I'm 5'11" and my back measured 21" that is going by their pack chart, but maybe I could use a large. Your input would be greatly appreciated. The pack in question is the Muira 50.

Hey John...I am 6'2" and have the large Muira. It fits me but is almost too large, it really is a tall pack, from waist belt to shoulder straps. Everyone is different, etc, but at 5'11" you'll probably be happy with a regular.

John, you need a reg.I have similar measurements and reg. is perfect for me.

Thanks guys, great info I was thinking regular as well, the problem is I have to wait until the spring models come out as they are all sold out in regular size. So I'll wait.