For what it worth.
I noticed a big difference in notification timing between
Outlook and Droid.
My Droid notify me at least 20 to 30 minutes ahead of Outlook (Outlook is set to receive every 3 minutes)
Did you notice something similar?
<edit> thanks to friendly sticky, changed deterrence to indeed difference, don't know where it came from!</edit>
[edited by: henry0 at 12:42 am (utc) on May 31, 2012]