Don't Install It If You're Worried About iOS 9 Problems
If you're having a great experience with iOS 9.0.1 or iOS 9.0, you might want to hold off for a few hours, days or even a few weeks. With iOS 9.1 coming in a few weeks, there's less pressure on you to install.
iOS 9.0.2 problems are inevitable and there's a chance you'll see an issue (battery life, connectivity problems are common) on your phone or tablet. There's no way to predict if you'll see something. You're always taking a risk.
The only thing you can do is sit back and wait for feedback to arrive. iOS users will post their feedback about the iOS 9.0.2 update in the hours and days ahead and you'll want to dig into that feedback to make sure the update is working out well with your specific device.
This is especially important if you own an older device. We've heard that iOS 9 performance has been dragging on some of Apple's older models so you'll want to be extremely careful with iOS 9.0.2.
Wait until you're confident about the iOS 9.0.2 update. That could take a few days or a few weeks. Be patient with it.