Generally, later revisions are better because they fix the bugs present in earlier versions.
In this case, it's even more acute. Apple had huge issues with the release of 9.0. I got a free replacement iPhone 6+ for the price of a screen replacement because my old phone would not boot when restored to iOS 9. The Apple genius told me Apple was having a lot of issues like that.
Additionally, app thining is active on 9.0.2 and not earlier. That's where a version of an app is tailored to your device when you download from the app store. That keeps file sizes down.