Pros

1. Very intuitive
2. Shortcodes allow you to create filtered views which can be imported as separate calendars
3. Filtering by Categories and Tags allows one to create very specific views (e.g., all "soccer" events or all events involving "grayson")
4. Recurring events handled simply and intuitively, especially using patterns (weekly, daily, etc.)
5. Extremely smart handling of recurring events, using base events and instances.
6. Agenda View — one of 6 — is great, especially for small screens
7. Streaming view and Posterboard views also good, especially for mobile
8. Can be imported into Apple calendars, Google Calendars and others - HUGE
9. Supports event featured images and category images
10. Import other calendars (not tried yet)
11. Add-on ($29) allows CSV import (not tried yet)
12. Intuitive method for editing (and detaching) an instance
13. Supports Clone-Event and Clone-Event-as-Draft