Less.
When I use modules, it's within the context of my own campain and world, so I throw out most of the characterization exept the basics (though in some cases that too) and refit them into the larger scope based on the usefulness of the character or their role.
Earlier this year, I ran Last Stand at Outpost Three from Dungeon 110. One NPC (Gorgoreth) was completely reworked except that he commanded the outpost--and that includes the character sheet--and played a significant role beyond the adventure. Another (Laalarash) stayed basically the same, but stuck around a little while to torment the PCs. Finally, I filled out the persona of a very minor NPC (Halaak) who ended up recurring after the adventure, and likely will again in the future.
I'd much rather see effort put ino developing high quality, flexible adventures.