I’m confident that mail and sms show up as the notification icon, but they’re bundled so they all look like one “notification” on the watch face. Not sure on the calendar side - I specifically block a bunch of app pushes to my watch because my phone is mostly a distraction when I work, so I don’t like my watch buzzing for every little thing.

I do get high/low temp on the face, which is very handy. Plus it’s always on (LCD, not OLED) - not as pretty as some, but 5 plus day battery life.