CAS and sim pathing.
When I first heard TS4 was coming I was so angry. I wasn't going to buy it, but shortly before release I tried the demo and fell in love with CAS and the sims themselves. I liked the way they moved, looked, interacted with one another, and always gravitated toward each other. They're immersive and for whatever reason I related to them like I did my Sims 2 sims. It was a good feeling, and one that I didn't realize I had missed in TS3 until that moment.
I decided to pick the game up and check it out. There wasn't a lot to do in those early days, but I built this tiny house (like the ones I used in TS3) and was amazed at how well my sim navigated through it. There was no foot stomping or getting stuck on obstacles that shouldn't be obstacles... it was wonderful. I was thoroughly impressed, and the damage was done.
When I got bored (there really wasn't much to do in the beginning lol) I tried to go back to TS3, but I couldn't build the tiny homes like I could in TS4. I mean, I could build them, but I couldn't invite sims over and have a small gathering without a lot of routing issues. It bothered me a lot more than I thought it would, and when my game froze yet again, I forced TS3 client closed and never fired it up again.
Since then it has been TS4 only, with a bit of TS2 Castaway on the console and some Sims Medieval mixed in for variety. lol
