PaulHudson - 1:06 am on Nov 5, 2010 (gmt 0)
Can't speak for developer support.
But the G Cal syncs well with iCal. Only 1 alert can be set rather than two and you have to add the event through Google Calendar and then the alert on your iPhone.
Other than that bit of overhead it's reliable and efficient. I'm not a heavy user but a happy one. :-)