What I don't like about the US one is the picture of Marty and Doc both looking at their watch (it's like the BTTF2 poster but Doc is wearing his BTTF1 clothes). It looks really bad. I don't know if it's original art that was never used or a modern photoshop botch job, but either way it looks poor. The more recent 4 disc box set in the UK has the silver logo on blue you speak of, plus a picture of the delorean. I must admit it's pretty cool:

http://www.bttf.com/dvd/BTTF_Digi_Slip.jpg

http://www.bttf.com/dvd/BTTF_DigiPak_3D.jpg

http://www.bttf.com/dvd/BTTF_Full_3D.jpg

http://www.bttf.com/dvd/BTTF_Digi_Outer.jpg

Hmm, you know, looking at those pictures, if I can find that for cheap before I leave, I might just buy it...