What aspect of The Sims 3 would you like to bring back to The Sims 4?

I had a difficult time choosing just one as I would like to see all of them. I have been playing Sims 3 more recently and had forgotten the depth that the characters and relationships had compared to Sims 4. I would like to see that as well as all of the options for color variations and pattern variations that we had in Sims 3. While I was not enamored with all of the stuff packs, a lot from the game and expansion packs would be great to have in Sims 4.

Seriously, I wish they would just update Sims 3 with the detailed CAS and object placement options we have in Sims 4.