Let's talk about the localthumbcache.package file...

Before Lovestruck, I could start a game with 7 played Sims, open my Library to show all saved Sims, open Neighborhood Sims, change outfits on the 7 played Sims, open every option under cooking us MC Command Center to show every Sim in the game, then save and exit.  My localthumbcache.package file would be maybe 27-31 Mb.  With Lovestruck, it now exceeds 47Mb.  I don't know about anyone else's game, but for me, the closer the localthumbcache.package gets to 60Mb, the slower my game runs.

Maybe it's time to start breaking the localthumbcache.package into multiple files.  Household Portraits, Dresser, Other menus with thumbnails, Game Info, and so forth?  That way, a player wouldn't need to spend so much time reloading things that don't change (especially the cooking menus).