indycutie Sims 4 is a very different game, and I wouldn't recommend it if you're looking for a bug-free experience above all. I think Sims 3 is actually easier to get running well these days.
I'm still happy to look at your save, or at a dxdiag in case there's something on the computer side that you can address. Delays are typically due to the game engine getting stuck processing too much data, or the computer's processor not being able to handle all the tasks it has in a timely fashion. The first has various workarounds, which is why testing a new save in Sunset Valley can be useful; the second may be fixable as well, depending on your specs.