I don't have lag in game play but I do when accessing build/buy mode and in CAS. I don't have WA, have lots of CC but I had lots of CC before patch 1.7 and never had lags. I also get a graphic lag when changing floors in game. It takes a few seconds for the graphic to go from gray shapes to normal. Never had that before 1.7 either. My graphics card is adequate, Gforce 9400 with 1Gb ram. I have deleted caches and am not saving all my user created stuff like I did before. On a side note - before 1.7 my caches (compositor caches, I have 2) would stay around 2 Kb and now are around 20,000 Kb. Why?
I never had the huge cache files when I played with the EA story mode enabled; but if I turned it off, then I'd get the huge files. I really noticed this with the latest EA patch because my game would crash at 1 a.m. unless I turned it off. Now, I have it enabled again with the latest AM story mode enabled, but the file sizes are still huge. I routinely delete the caches between game plays.
I have 1Gb devoted to RAM and 8Gb on my quad core and have more lag than before too even though I don't have WA. I rarely, if ever, went into a skeleton building and watched the objects appear before. Now it happens a lot, even outside on a community lot; but at least it doesn't take forever on my system.
We added 2Gb of RAM and a new graphics card to my mom's computer so she could play the Sims 3. Though she has a decent processor, her system really lags when assigning textures and colors to objects. She doesn't have any mods or cc yet. Her game is the base game straight out of the box with updates to 1.7.9.