Speaking my language
Indeed, my favorite aspect of the Fantastical lineup is its ability to parse your input as if you were speaking to a person -- a feature that works if you start with Siri, but something you can't do within Apple's own Calendar and Reminders apps. Instead of having to go through and fill out a form -- tap here, type here, pick date here, and so on -- Fantastical has one field as a main entry point for all types of events. As an example, you can type "remind me to put out the trash every Thursday at 6am," and Fantastical will create a recurring reminder for you to put out the trash at the requested time. You don't need to hunt-and-peck your way through a picker in order to enter the event like you do with the Reminders and Calendar apps in iOS.
The same can be said about calendar appointments. Entering "lunch with Jane on Tuesday" will set an appointment for noon on Tuesday. Going even further, you can include the location of the appointment or reminder, and Fantastical will enter it on your behalf. In my opinion, second to combining Reminders and the Calendar into one app, this natural language implementation is the biggest selling point for the app.
With the latest version of the app released in December, 2014, Flexibits made the natural language recognition for searches even better by adding abbreviations. Now, you'll be able to enter common shortened versions of words such as "bday" instead of "birthday" to save you even more time finding the event you're looking for.
Of course, if you prefer the more traditional input method, Fantastical has no problem with that either.
In all fairness, if you start with Siri and speak these same requests, appointments and meetings will be added to your calendar and reminders, but I really like that I can do it all just within Fantastical.
iOS 8 only
With the latest version of the app, you get new features that could only work using iOS 8, so you'll need to have upgraded to the latest operating system to use the latest version of Fantastical.
The biggest recent change is the addition of a Fantastical widget in the Notification Center. Now you'll be able to see a day view that shows your scheduled events and appointments where they're handy without opening the app. You'll also be able to snooze alerts and designate a reminder as completed directly from within the widget.
Fantastical 2 for the iPad is hands-down a better approach to the calendar than Apple's, and that translates into a better overall experience for appointments, reminders, and managing your time. There's some work to be done on the amount of information displayed (particularly with the agenda list), but it seems like an easy fix.
With that said, I feel there's currently no better way to organize your schedule on the iPad than with Fantastical 2. While Apple gives you the tools for the same functions using Siri, Reminders, and Calendar, it's just easier doing it all in one app.