The CICAL_SLOW_SYNC took under 2 min to read the calendar, that's not too bad.
How many times has it done the CICAL_SLOW_SYNC fro this user?
It is the device requesting the CICAL_SLOW_SYNC. So either calendar is being disabled and re-enabled over and over again on the device, or there is some other reason the device keeps requesting a CICAL_SLOW_SYNC.
Get device event logs, and look for "net.rim.calendar.ota data:SYNC". This is the start of a slow sync request for calendar on the device.