I wear birkenstocks almost exclusively, so I am not unfamiliar with the brand.  These were really stiff when I first got them, tho, and took quite a while to break in.  Once you get them broken in tho, they are very comfy and they form to your foot.  I bought these in B (Medium) width, and I should have gotten narrow.  They are a bit wide for me.  Birkenstocks run wide and I just made a mistake in ordering.  Oh well, they are still some of the most comfortable shoes in my closet.