I love it too.I had the same issue on my iPad Pro 9.7" - as well, no problem with my iPhone 6s+. I was able to get it done on the iPad by deleting the 9.xx beta profile first, then asking software update to do it's thing.
If you have been using the beta versions of iOS 9, go to settings, locate the iOS 9 beta profile and re-inquire ( if you've already downloaded)
I've had zero issues with syncing playlists, all my iOS 9/el Cap/shared library and playlists match perfectly.
I guess I'm in the minority, as I love the new Music app. Page one. Choice one. "Playlists". That's ALL I needed to be impressed
As well, I'm going to be using it through GM release this fall. I've been thoroughly impressed with its stability and ability to continue using the vast majority of my daily apps. Apple doesn't make most point releases (unlike 7's major facelift) incompatible with apps on the platform right away ... and if incompatible issues arise, it's usually resolution and UI challenges, teething pains they went through during the quadrupling of rez iPads and iPhone increasing height as well as scaling with the '6' devices. Xcode has kept up and been brilliant with app resolution scaling changes on the simulation.
I'm also wondering if the 'lag' and non-fluid UI experiences are relevant to the devices with < 2GB of RAM - as it's definitely the last thing I'm experiencing ... either on iPP or iPhone 6s models. Mine has been as fluent as iOS 9.3.4/5 - can't remember which I had before the 10's installation 48 hours ago. Especially the 3D touch additions and 'layered' - much better and easier to 'see' before acting UI ... with some phenomenal 'locked' phone interaction and ability without unlocking.
No problem with working with my watch. Messages is insane. I love it, as well as little improvements I'm noticing everywhere. For instance, go to store and updates and notice the unnecessary button to 'update all' now. Maybe it's reserved for cell updates, I'll try tomorrow but @ home & on WiFi, all updates immediately are 'updating' when they 'pop up' as fresh - in need of an update apps.
Widget management will now become more important and I think widely used as it's there - on the lock screen left camera right. No mode lower right corner for cam and middle or left lower for control panel.
Also the very cool 3D touch options ON those control center 'Micro-Apps' like flashlight dimmer and regular timer settings. Definitely helps bring forward key areas like 3D Touch, notification shade and widgetry to folks (like my parents) who'd never use them, they're hidden from Average Joe n Jane. The geeks like us know the tricks but for many it's still phone (& maybe camera) first and foremost. Flashlight, day planner, maps and third party apps are all tertiary, as Messages and FaceTime are secondary apps (& already included) for them still, and they have zero need of interest in App Store downloads or options that mirror Apple/iOS apps and improve the experience. Ala Fantastical.
Got a lil long, my bad. As such a major release that takes advantage of the newer hardware facilities, I'm going to live with the beta system, enjoy it and I'm sure pass along some hints in September, October to family & friends just updating to the Public iOS 10 release.
(Messages is VERY )
J
Took a reboot of my iMac to have my iPhone 6 detected by iTunes and flawless sync of playlists from then on.
A bit quaky with regards to my widgets but nothing to make me look back.
