This year I started using the iOS 10 beta way too early. Today it released and everybody can download it. (Hooray!) Here's a few random thoughts I came up with while using the beta.

Spend some time figuring out messages. There are several new features and you'll find use for at least a few of them. If you're feeling cranky about the animations, think about how one-dimensional text is. The animations and text effects can add context.
A case in point is stickers. I thought they were kind of dumb but I've been using them throughout the beta and now I like them. They may go from cute to unbearable in the space of a week but for now, they're still cute.
All my beta friends are mixed about raise to wake. It's really all about whether or not you like using Notification Center. Try giving the notification screen a go. It's better and more interactive with iOS 10. I think Apple views the notification screen as their version of screen widgets. I'm definitely using them more now than ever.
The improvements to Apple Maps are significant. If you'd given up on Apple Maps, give it another try. I particularly like the screen layout on driving directions. It's much better now. Maps also will dynamically re-route you when it finds a shorter route, which comes in handy often in Southern California.
You'll probably initially hate the new Control Center. I did. Multiple screens of Control Center seemed unnecessary and why on earth is the Night Shift button so big (or even there)? However, it grew on me. Now I kind of like having a separate Control Center screen for audio controls. If you connect your phone to multiple bluetooth devices, don't miss the source button at the bottom of the Audio Control Center. Also try using 3D touch.
Searching your photos by face or objects is fun. However, except for playing with this feature to see if it worked, I've only actually needed it a few times in the months of beta testing.
Photos' ability to collect images from an event or date is fun and we've enjoyed this throughout the beta. However, that thing where Photos gives you the "Best of" some period of time appears to be completely random.
I haven't seen enough of Siri third party integration to have an opinion. My fear is that I still will not have seen much of it six months from now.
Home Kit still has a long way to go.