I notice no differences except I had to uninstall and reinstall some apps on my Gear 2 to get them to work again.
I wish Wearable Widgets was still available in Samsung Gear app store. It still works great in Android Wear and even works in my Gear 2 with Note 3 but it is not in the store for Note 9 so I can't install it in my gear 2 connected to Note 9. Wish I knew a way around it.
My LTE reception is def no better. Might be a little worse.
I use Nova Pro Launcher so I probably don't see all the features.
Anxious to hear about any problems fixes or new features I haven't noticed yet!