When comparing Fantastical vs Outlook, the Slant community recommends Outlook for most people. In the question“What are the best scheduling/calendar apps that syncs across desktop and iOS/Android?” Outlook is ranked 3rd while Fantastical is ranked 10th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Supports multiple calendar platforms
If you're locked into using an Exchange account, Google Calendar won't work without 3rd party syncing options. Fantastical works flawlessly with Exchange and with Google Accounts so you can have both. It also supports iCloud, Office365, Yahoo, and Facebook calendars.
Pro Fantastical can comprehend natural language
You can copy and paste a line from a meeting note and Fantastical can copy down and present the relevant information
Pro Beautiful and highly polished design
Cons
Con Expensive for a single utility app
Fantastical on OS X costs $49.99 and an additional $4.99 if you want to use it on iOS.
Con Only supports iOS and OSX
Fantastical doesn't support web, Windows or Android.
Con Designed to be used with your email as well
Outlook isn't just a Calendar app, so the UI is a lot more complicated and has unnecessary components if you don't plan on using it for your email as well.