Thing 8's theme is Calendars. I have tried various online calendars over the years: Outlook on my home computer as a standalone, Lotusnotes at work, Outlook at work, work calendar synced with work phone, work calendar sending invites to me on home calendar and so it goes on.
I did try Google calendar a few years ago (and know plenty who use it) but I think the key thing was that my work calendar which was critical was on Lotusnotes and then Outlook. So Google calendar was only ever going to be a duplication for me. Finally I got to a stage when I abandoned my personal Outlook calendar and just used my work Outlook which synced with my work phone for all personal and work commitments. Of course, that led to some loss of data in terms of personal appointments (eg recurring ones) and contacts when I left that POW.
These days I am pretty happy using the native calendar interface on my iPhone. Via iCloud this syncs across various iThings. It also allows me to add calendars from other sources eg Google, Yahoo, as well as iCal. It also syncs with my Facebook invitations and events. And now there is also an iCloud sync with my desktop Outlook so I have even started using that calendar again.