Mals were bred for heavy pulling, sibes were bred for speedy pulling. Sibes were also bred to be with the human family, and are said to have a more people-friendly personality than the mals, but I don't know, I've met some pretty friendly mals. I've heard mals tend to be more of a one-person dog. As mentioned, mals are much larger, and have brown eyes. There's a great site called Everything Husky that carries tons of info on all the nordic breeds.

www.everythinghusky.com