I'm only now going to buy all the seasons, I know all 6 were released individually in carton digipacks (without plastic trays) in the US, but were they all out as such in the UK as well, anyone knows?
Search here in the Digibook section of the forum doesn't seem to work ("enter valid text" constant error), Blu-ray.com lists it as "Slipbox", whatever that means, and Amazon pages are a mess with various images, versions, and resellers...