Totally onboard with the changes. Much more scalable but I do have a few caveats.

I personally feel like Search fits naturally better in the top nav. This is because the territory selector can become a search field instead of going to a separate search page. Showing in-line results & filters below, as you type. If the time comes to make that switch in future, the search bar will have to animate to the top of the keyboard on mobile devices and obstructing any possibility of seeing the results below.

The SN logo could probably also remain up there, as an alternative to the back button. Both are core navigation items and so being at opposite ends of the screen feels a touch strange.

Love the sidebar and sticky elements. I’m sure this will unlock a bunch of new features like teeny-territories & more, so can’t wait to see what else is brewing.