I got the UK set at roughly half the cost of the U.S. release. The extras are identical and the UK release is region free.
The quality of the new HD masters is outstanding. I've seen these films in various formats over the past 45 years, including 8mm, 16mm, 35mm, Betamax, VHS, laser disc and DVD. I have never seen them look and sound this good. The quality is superb.
My only complaint is the unnecessary tinkering with the stereoscopic window on CREATURE. This article explains what was done: http://www.3dfilmarchive.com/an-in-dept ... k-lagoon-1
In short, the set is outstanding and HIGHLY recommended!