Keep An Eye on the iOS 9.1 Release
You'll want to keep an eye on all future iOS 9 updates as they progress through the beta process. This includes the iOS 9.1 update that's set to arrive later this year alongside the iPad Pro.
The iOS 9.1 update is currently in beta which means you can track its new features and its performnace. This will help you get a better read on whether you want to install it on your specific device right when it comes out.
iOS 9.1 probably won't be the only iOS 9 update that goes through a beta process and you'd be smart to track any and all updates that go through Apple's public and private betas.