For a program that has a lot of synchronization options for calendars, it lacks one important one: you can't sync account information or other settings, like Calendar Sets, between multiple computers running Fantastical (I have two), or shared feature settings between iOS and OS X. This means setting up Fantastical from scratch on each device and, when a change occurs, managing it on each device as well. The company opted to not use iCloud for syncing, as it offers the software in the Mac App Store and directly as well, but there are many other sync options for these kinds of configuration details.
A powerful replacement
Fantastical's overt simplicity and hidden depths may not be for everyone. But the company made distinct choices based on years of developing its iOS version and previous OS X release. Making design choices instead of throwing everything into the mix produces both good software and sharp contrasts--it's less likely to be for everyone, but more likely to serve quite well those who find the choices appealing.
If you find Fantastical's event-list centric approach, in which upcoming events are nearly to-do items alongside actual reminder entries, matches the way you want to manage your calendar, and the natural-language entry an appealing way to avoid adding events, it's the right program to pick.
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