Hello!
Today I downloaded the new iOS 9.0 GM seed, 13A340 to my iPhone 5s and backed up my iPhone and then I installed the .ipsw by holding the option key and clicking the restore button in iTunes, as usual. And I installed it but when I look i have the 13A341 Build, don't know why... and when o check for updates OTA on my iPhone, i can find iOS 9 Public Beta 3 as an download... I think something is not right.