It really depends on your feet as to which of the comfort brands (i.e. Birkenstock, Dansko, Born, Clarks, Sofft, etc.) will feel best. Birks are great for people with wider feet, although they do make narrows, as well.
I've tried Dansko, but overall they are too narrow and constricting for my feet. Birkenstocks are perfect for me (I can walk all day in a brand new pair and feel fabulous), but I have friends who cannot wear them.
So I guess what I'm saying is that no one else can judge whether Birkenstocks are right for you. You can try wearing them for a limited amount of time and hope they break in, but for some people they will never feel right.
As for looks, I agree they aren't sexy, but no one buys them for formal wear anyway! They are great, cute, comfortable and casual shoes for most people.