The game won't be absolutely perfect. No PC program in history has been totally bug free. However, I suspect that it will be far less buggy than Sims1. One of the main things that they seem to have been working on has been making it crash resistent. So, I suspect that it will be a lot harder to crash than TS1 was.
I always hated how my Sims game crashed. At points my computer quit running the Sims entirely. It was very annoying.