I was a Sperry devotee until I bought my Sebagos.  The sole on the Sebago docksider is much more sturdy, and the leather is stiffer.  Like the boatshoe equivalent of a Red Wing boot, they need to be broken in quite a bit before they look cool.  The Sperry has very soft leather and a very spongy sole, and it breaks in very quickly, but also wears out just as quickly.  After a few months of heavy, barefoot wear, the Sebagos have a broken-in look and feel, but also seem like they will last years longer than a pair of Sperrys.

I got the redwings as my first ever pair of boatshoes for my holiday and liked them so much I even considered wearing them with long trousers.