Well, the Balenciaga bags are goat leather. I think this is why they are supposed to be so soft. I don't have any other goat leather bags, so it's hard for me to generalize.
Goat is a much softer leather...but should be careful...it can be damaged easily....Calf holds up better...but can scratch...too I personally like Goat better
Goat skin is actually tough, but because Balenciaga SEVERELY distressed their leather (ie. beat the H out of it), the B-bag leather is signaturely soft.
Calfskin is thicker. My personal fav is lambskin, of course. It's soft and luxurious.
