Both the 200S and the 2000S cabinets are 15" deep. The cabinet depth isn't the issue, it's the folded port. The 2000S is 6" taller and 6" wider than the 200S so it's roomier inside.
About a year ago I planned to take accurate internal measurements of both and post them, but never got around to it. It's a major pain unbuttoning one of those beasts.