Oh I have got to pitch in here!!
I confess, I am a huge addict. My laptop died a while ago (hence why I was totally MIA for a while!), and all I could think of was "I can't wait to get Sims back!!"
I have all the expansions, but only the first two stuff packs. I also have far too many mods and custom content.
The lots do load slower now, but I just do go anywhere very often, solves that problem.
It's funny, though... When I start up Sims, Evie *always* decides it's time to cuddle, and hops up on my lap, forcing me to move the laptop out of her way. So it doesn't load slow enough! It gets loaded up and sits there staring at me begging me to play while Evie is still keeping me occupied!