I began with Sims2 years ago. I found Sims3 lacking in so many ways compared to the Sims in Sims2. I'm not surprised that those of you who's first Sim experience was with Sims3 finding something similar when you switched to Sims4. For me, the Sims in Sims4, are far more full of personality than they ever were in Sims3. The traits did little to alter their interactions in Sims3 as well. While I did play Sims3 everyday for hours at a time, I had a love/hate relationship with it. I started using mods in that game just to stabilize it (and I was playing on a gaming rig). I use mods now, to augment the game itself in Sims4. Slice of Life has a terrific personality system that will affect how the Sim interacts. I'm having the time of my life again. :)