I think a lot of the praise for this movie stems from Terminator 3 syndrome. Mainly that people are so used to getting their movies pissed on, that a decent sequel becomes somewhat surprising and a relief from the mediocrity that we all imagined in our heads.
However, my problem is Die Hard should have never had a "decent" sequel, I felt that whomever took over should have attempted something that thrilled as just as much as the original.
I've noticed the biggest problem always lies with Hollywood hiring insecure directors to take over from creative masters. I could just tell from Jonathan Mostow's (sp ?) interviews and approach that he wasn't going to attempt to top Cameron's work but try to deliver something that honored it.
Nothing angers me more than hearing a filmmaker pull a Lucas and say: "We'll never meet the hype" and just never try. I want ballsy directors taking over from masters and proving themselves by trying to top them.
You give a Die Hard film to the director of Underworld, you'll get a fairly entertaining film like Die Hard 4. You give an Alien film to someone like James Cameron and you get the ballsy Aliens.
There should be some kind of ambition test given to directors before they take over a franchise. If you don't think you can improve on the previous work then hand it over. I don't want directors who idolize previous films in a franchise as well as their directors, and end up giving me fan fiction, I want directors who try to deliver something more special than what we've seen before.
That aside, I personally think the Die Hard films went in the wrong direction by having bigger and bigger threats, I thought the best thing about Die Hard was the claustrophobia. They should have had Mclane getting out of tighter and tighter spots not out saving the world.
Either way, with the budget they had why not sacrifice some of it to hire an established heavyweight filmmaker. Imagine Die Hard in the hands of Cameron, Scorcese, Ridley, hell even Michael Bay or Tony Scott would've at least given me something. Dumb fun, but ambitious dumb fun nonetheless.
To me Die Hard 4 was solid fan fiction. Nothing more.