Just wondering about that "ALIENS" special edition DVD that was re-released at a 2-disk in UK, as I'm deciding whether to buy it or not. I already have the original single disk package. Apart from the extras, is there any difference in the feature film if I buy the 2-disk version? I understand it's the same version of the film, but is there any improvement in picture or sound quality? If not, I'll stick with what I already have. Thanks.