Q: A question on rebasing - from http://support.microsoft.com/kb/933146 scenario 2 - (suppress all) If the solution is not used for all mailboxes in the organizations, some users’ items will not be rebased - what is the downside if we use suppress all against ALL mailboxes including resources?
A: If you use ‘suppress all’ against all mailboxes, then no updates will be sent to attendees when a meeting is updated (suppress all suppresses the updates that would normally be sent). This isn't an issue for a single-instance meeting (only exists in one user's calendar), but users would need to update any meetings that involve other users manually afterwards.
If all users are rebased using suppress all, updates that are made prior to patching/rebasing will be impacted in that an update will not be sent. Using the ‘suppress all’ switch is that the person who scheduled the meeting will see one time, and other attendees will see different times in their calendars afterwards. If you use the switch, you would need to advise your users to check and update any meetings to make sure everyone knows the correct meeting time.