The best thing that no other Smartphone platform like Android or Windows Phone have was the perfect 100% offline Sync between an iOS Device and a Mac. The iCloud is there, but the Users can also sync the Devices offline.

But now, Calendar, Contacts, Notes and Reminders are only sync-able with iCloud (or IMAP). 

We want a 100% offline Sync with also Calendar and Contacts, because:
- not all like uploading personal data to servers far away if not necessary
- old-school: my data only on my devices!
- the servers are not in our control - but it is our very own data
- servers can be hacked! (or other bad things can happen)
- in business, clouds are often not allowed because of data security

Apple, please bring the 100% offline Sync back!