If your not having any issues on 4.3.1 id just stick with it.
Is anyone here actually having trouble with FaceTime on 4.3.1? I've used it a few times over 3G (My3G) and all went well. I did a search for FaceTime issues and what I found was some saying it doesn't show up in Contacts and others having connecting issues. I haven't noticed either of these problems. Did I luck out or is it only happening every once and a while?