Well, thanks for your inputs. My last iOS upgrade was from 8.x to 9.0.2 and I had to wait forever for many apps to be updated! Several were still not updated after months and months of waiting and then I just gave up and bought my 6s with 9.1.
I decided I'm sticking with 9.1 until final 9.3 is released and perhaps a jailbreak. I'll update to 9.2.1 while the signing window is still open, depending on initial app compatibility reports. It's gonna be a tight squeeze for me, if a 9.2.1/9.3 jailbreak were to be released soon after final 9.3 is released. Ideally, most apps will still work on a 9.2.1 jailbreak. I'd rather not end up stuck on 9.1 when the 9.2.1 and 9.3 signing windows close. Now, if a 9.2.1/9.3 jailbreak is not released soon after 9.3 is, then skipping 9.2.1 and upgrading to 9.3 is a gimee. It just wouldn't matter.