I just took the plunge and bought the Vampire pack along with the other one I was missing Realm of Magic, but have yet to install either of them.
Is there a way in the game options to check a box to 'not have them in game'? The option is there for Seasons to disable weather options, and we do have option to disable NAPs in Eco Living. I was hoping there was a feature for this with Vampires and even Realm of Magic. It has been my sole reason for not buying the packs. I do not like playing with mods, however appreciate others do like them and use them. I am really hoping there is more of a default game option rather then just locking doors (no trespassing).
I would love if they implemented this feature if they have not already, as I do believe it would give more incentive for others to try this pack if there was a feature to disable it when they do not wish that particular game play in certain saved games.