I like the zoomable/scrollable view that's a UI improvement. The add event form could do with some UI tweaks. I'm not the biggest slider fan, but that might be a better control for the reminders (with sticky graduations) (instead of a dropdown) and reduce the length of the form.

Some autocompleteness on the 'Where's could be good. Can you make time input easier?

Shifting between calendars needs to be very easy. I used to use Gcal, and I was forever putting events in the wrong calendar.