I'm just curious which Sims 4 EP or whatever is considered to slow the game down the most. I don't really have a laggy game, yes the game can take its sweet time when getting back to it after the computer's been in sleep mode and the initial loading could be quicker, but it's not awful or too slow. But I was wondering as I know adding more can slow it down more which add ons are the worst. I'm only interested at this point in time in adding Growing Together, Island living, Wedding stories, and Get famous. I know btw seasons could very well likely be considered the worst, but I already have that one without a problem

IMO just add one by one in order of what you want most and know it will slow a bit with each until you decide you are at max you and your hardware can handle.

You may start notice an increase in loading times, due to extra content, be as you say I would say it would be Seasons too, especially during a snow storm with many sims on the screen at once.

I have all the packs (and kits) and my game still takes less then 2 minutes to load. Loading screens in-game don't take long either. I don't use much in the way of mods or cc though. I rarely have lag in my game.

I agree that you should just add one by one and see what your hardware can handle.

Being in total agreement with SleepycatDSL, there is simulation and loading lag added by all the EPs. However, I have played with and without mods added, and I conclude that it is mods that are the real killers. Even the lag delivered by Seasons is nothing compared to what some mods - and some CC - add to the game.