The official update feed from the Google Apps team: SLAs available for Gmail, Google Calendar, Google Docs, Google Sites and Google Talk:Google has been comparing their App up time to traditional services, and boasting how much better they are.
... Google Apps Premier Edition now includes a 99.9% uptime guarantee for Gmail, Google Calendar, Google Docs, Google Sites and Google Talk....
My experience is different.
For example, today sharing stopped working from one my Google Calendars. Very annoying.
I run into a variation of this sort of failure every few weeks. Of course my XP work environment is also unreliable, but I ask more of it.
Personally, I'd give Google a "B" grade for reliability. Not B+, but not B-. Just B.
Update 11/2/08: The iCal calendar continued to show an update error icon, and I couldn't connect to the gCal share with a browser. I recalled that Google Calendar has CalDAV support and so does iCal, so I followed the subscription directions.
Around that time it finally occurred to me that I own Spanning Sync. Now Spanning Sync only syncs with one Google account (our family domain), and that's not the account that has my work calendar, but that's no problem. My family domain account has read/write privileges with my personal gmail account calendar, so I could reach it through this indirect route.
It seems to work fine. Spanning Sync support means I could theoretically update the work calendar from iCal or even my iPhone, but I don't plan to try that -- ever. The arrangement is too rickety to support true synchronization. Publication is fine.
I have given up on .ics subscription.
PS. I like the way the CalDAV accounts work in iCal Leopard. It's a positive sign in several ways ...