I wouldn't get too excited about these. For the last few years UK publishers have been releasing "special editions" and signed limited editions that are little better than their (very poor quality) standard hardcovers but at a significantly higher price.
I doubt that is leather on the spine (faux or otherwise). The covering is likely to be paper over board, perhaps using a better quality of paper than most UK hardbacks. They might push the boat out and use acid free paper for the pages or a sewn binding rather than perfect-bound, but I doubt it at the price level they have set.
Buy the standard US hardcover instead, it is likely to be better made, will last longer and will be cheaper even with shipping factored in.
I decided to attempt to prove you wrong by preordering. I just realized amazon.co.uk now offers 'free super saver delivery' to my country.
Might end up being a silly decision, but oh well.
Macro photos and a merciless review of the book's quality will follow. Please keep in mind that I don't exactly have a library to compare it to, though.