|Buffy the Vampire Slayer-Season 6 Box Set Part 1||R4|
Region 1 is only about to get Season 4. Region 2 gets this season almost the same day as R4. The R2 and R4 discs will probably be exactly the same again. The R2 packaging is the same as last season, which is nice (I like it, although the Season 5 version felt a bit "cheap" — this one is a bit better). The R4 packaging is the same as all the other seasons, too, with a set of standard Amarays. Choose the packaging you want, 'cause that's the only difference between the R2 and the R4.
Note that there's a much bigger difference between these and what we expect to see in R1; you have heard, I'm sure, that Season 4 is being released full-screen in R1, after being wide-screen in R2 and R4 — it's expected that future seasons in R1 will follow suit. I won't recap my reasons for preferring the wide-screen here, but...
New: the R2 packaging lists another extra on disc 2 — an Easter egg (which apparently shows some candid footage of a signing held at Tower Records).