I wish the people who released this set had waited till the fourth film was released (they had to know it was in the works) and then released this set, but they didn't wait, so this set contains the first three Die Hard films.
We love Die Hard 1 and watch it every xmas eve. The DVD in this set replaced our third worn out/over-watched VHS version of the hit.
We watched some of the items on the Special Features/Bonus disc, but we could take it or leave it. We felt the same about Die Hard 2 and 3. They were nastier, grittier, ruder, and gorier than the first one (or the fourth one).
We love Die Hard 4 and watch it every July 4th (bought it separately). Although it isn't included in this set, I think this set is still a good set, and you may find the Special Features enjoyable. But if you like it lighter and brighter, so to speak, you may want to just buy Die Hard 1 and Die Hard 4 ("Live Free or Die Hard").