Because Apple removed Home Sharing in iOS 8.4, I stayed on 8.2 and patiently waited for 9.0. Apple "promised" to bring it back in 9.0, and they actually did!
My iPad Mini can easily store a couple thousand ePub's, since they are relatively small files. However, my 1500+ high bit rate MP3's were more than the Mini could handle. I keep them on my desktop (several terabytes of storage) and use iTunes to play them on my WiFi network iDevices through Bluetooth speakers.
I tried streaming the high quality MP3's from the cloud, but I have fairly slow DSL and had stutters/pauses in playback. My in-house network works perfectly, so I'm glad that Home Sharing has returned! Now I can give 9.0 a try.