I finally am starting to use google calendar more for my day to day appointments, and it really shines. Appointment request works perfectly with or without Outlook(like if the recipient uses Outlook or someone uses Outlook to send you a meeting request). The calendar app itself is awesome. You can create multiple calendars, even subscribe to public calendars that are in iCal format, I have done this with all my meetup groups. There's also calendars for US holidays as well as Chinese holidays.