I loved the "meaningful animation"[1] for location pin after you create an event. At first I thought Material Design is a lot of buzz words with not much innovation but when I read the docs I realized they put a lot of thoughts behind it.
Their assists animation looks interesting, but I will wait to judge until I can actually try it. The Apple calendar looks great, but feels really clunky to add and edit events. (Especially on a Mac!)
For pure usability, I haven't found a calendar program that beats MS Outlook running on Windows.
Can you elaborate on what you mean by "clunky"? I haven't noticed any issues adding or editing events, in either OS X or iOS's Calendar apps.
Also note that Yosemite added event suggestions when adding new events to the OS X Calendar app (but I don't believe iOS added anything like that for the iOS app). I haven't had a chance to experiment with it yet (since I primarily do event entry in iOS), but it looks pretty straightforward.
Consistent choreography. Do: Direct user attention with coordinated, orderly motion. Don't: Don’t confuse users with inconsistent or disorderly motion and objects leaving/entering in seemingly random directions.
This seems like a strange hard rule to follow. The disorganized demo has a very different "feel" to it that might be appropriate in some places more than others.
From my viewing, the "feel" is chaos. Why are they all moving different directions? Does it mean anything?
Watching the Don't video legitimately hurt my brain; the only way an app can justify that kind of choreography is if disorientation is an intended part of the emotional experience.
The "Don't" video looks like billiards balls on a break, which might be the feel certain apps are going for, particularly games. It doesn't make sense for a productivity tool like Calendar, obviously.
It's also just a guideline, a suggestion, and if you think your app would benefit from having items fly in and out in all directions, if that's the feel you want to give your users, that's your choice. It's just probably not the right choice in most cases.
[1] http://www.google.com/design/spec/animation/meaningful-trans...