What makes fantastical great is how intuitive it is. You type lunch with Michael at 3pm on Tuesday and bam it's all set
And you can't do that with Siri, and the native App?
Are you being sarcastic? iCal is the native calendar app in OSX, and in iOS for all I know ...I heard of a new app called iCal, but I never use the calender except for checking what day it is. iCal syncs perfectly with other online calenders. Not sure if that's what you're looking for.