This is very much a matter of personal preference. For me, I prefer the Sims 3 graphic style. I prefer the level of realism in the graphics of sims 3. For me the graphics of the Sims 3 are balanced. It is real without being too real, cartoony without being too cartoony. I think graphics style is a contributing factor to immersion in a game like the Sims. I will try to illustrate what I mean.
I create for both the Sims 3 and 4 without any CC. The first picture is from a gothic styled home I'm building for the goth family.
http://i876.photobucket.com/albums/ab325/petalbot/gothyard4.jpg
This picture picture just sucks me right in. The grass has texture, the trees have tree bark, etc. It feels so natural without being jarringly real.
These are pics from a couple houses I made in sims 4.
http://i876.photobucket.com/albums/ab325/petalbot/Moderna%20v2/out2.jpg
http://i876.photobucket.com/albums/ab325/petalbot/Maison%20Soleil/paint.jpg
While pretty, it doesn't pull me in the way sims 3 does. It is too cartoony to do that for me, I guess, in other words I can't relate to it as well. The rocks are unnatural in shape and texture. I feel as if I could walk up to one of those rocks, as if it would be made of plastic or paper mache, hollow inside, I could pick it up, throw it and it would blow away in a strong wind. The grass is unnatural in both texture and color, the trees trunks are unnaturally smooth and painted. It is a fake very cartoon world.
Maybe I would be able to get into TS4 graphics style a little more if it were not for the cardboardish 2d backdrops in the background beyond the immediate scenery of the lots, that to me is very jarring, and I think it is also the reason for the heavy use of blur (to try and blend it in with the scenery that you can interact with). One other thing that also really jars me is that the clouds basically scroll across the screen in a horizontal motion. Despite having a not very natural look, the move with a disturbing unnatural motion.
