I was thinking that we still had to buy the pack but we had options to turn off certain pack features. Like turn off vampires but still have CAS and build/buy items. Or with parenthood we could toggle ask for advice and or character values and still have the objects.
I would really just love more options. We should be able to choose if aliens and vampires etc appear depending on the story or game play we are doing. We can turn off fame for the Sims we play now but I sometimes want the celebrities gone from my game also. They need to stay in Del Sol Valley if you ask me. They just ruin my immersion into the game.
They whole partial pack idea is good over all if it's implemented correctly but I think others see it differently than I do. For one, it would not make the cost less because the partial pack idea would be implemented through game options. Each pack would have pack features along with CAS assets and Build/buy assets. So three total assets per pack in which we can toggle off and on. This is what I thought about when I read about the partial pack idea.
More options!
It may not be able to be implemented on older packs but future packs could have more asset based options.