I know in the case of apc's the black jeans are slimmer than the indigo, I think from the dying process. Have you had a pair of blacks before? I'd be curious what other people's experience is though, I think Fok just bought a pair so maybe he can chime in.
Just bought my first pair of rrl's during the sale, the slim one wash. Bought 32, have a pair of apc ns 31, usually a 33 in most pants. I hope they fit