I find leather such a hard note. Hard to find I mean.
Instinctively I think leather ought to be hard, be tough, be rugged, be mean, be in your face. But really, in scents, I find it to be a very light scent. The airy dry scent that's like sawdust when you sniff the back of a piece of leather. We think a scent that's a leather scent must be uber-macho, but really, leather is an olfactory fake out.
My favorite for this is Creed's Cuir de Russie. I also love the heavy Royal English Leather by the same house, but in the leather and iris creation that is Versailles Pour Homme, leather hides but unifies every part of the scent. You don't think leather when you smell it, or I don't, but then when you think about it the leather is all over.