An advantage of the Ultimate Flight IV package, if the box contains all it should, is that you will get the printed manual and key card.
A later release of "WWII Fighters" was re-packaged under the EA Classics label (c. 2000) and offered the manual as a .PDF document and also featured a redesigned installation interface. Otherwise, the game was exactly the same as the 1998 version except the discs came with the last official patch included. If you get the boxed version you should get the printed keycard as well. If you get the jewel-case version then I don't think there will be a keycard included.