First off let me say that I love Sims 3. I get kind of upset when I see other simmers say bad things about it. I don't say anything because they are stating their opinion and some simmers have had a buggy experience with even though I have not. So I will refrain saying things like the load times were minimal, and my sims are not robotic and lifeless.
With the Sims 4 I was hoping it would be like the Sims 3 on steroids. I am very disappointed that it isn't. Sims 3 offers much including multitasking, I've seen it. Sims 4 offers new emotional sims which intrigues me. The beauty of Willow Springs is very nice but there are loading screens. With everything that has been taken out of Sims 4 and everything I still have with Sims 3, I have little reason to switch. Once mods that suit my needs come out and I have cc to choose from I will try Sims 4.