Update after 2 days:
Soon after doing the update, my phone would run quite warm, and the battery was draining fairly quickly. Wiped the cache partition, but still no good. Uninstalled Google Fit, as some others had reported problems. The phone did cool down for a bit, but the problem returned. Uninstalled the Amazon.com shopping app (not the appstore), since I found that it was constantly running. I also removed DashClock and all of the extensions (not sure if that helped anything, but did notice that the battery extension was running even though it was not in use.) My phone did cool down and my battery life seems to have returned to normal.
It would be nice to change to a dark theme for the notifications, messaging, and phone apps.
Also there is a slight delay for message notifications to be sent to my Pebble.