I found Sims 3 to be much too high maintenance, and towards the end, overwhelming. It seems like I spent more time setting up & trying to fix things than actually playing. 4 runs so much more smoothly, and I can actually make substantial progress in my games. I'm also glad there's no store, I think all that content actually hindered rather than enhanced my games. I loved the worlds, but you had to have 18 saves going just to play them all. No wonder I never felt like I was getting anywhere in my games.
So yeah, how Sims 4 ends up remains to be seen, but to me it's the clear winner right now. And to think I almost passed on it.