Microsoft
I have a Law Firm that uses public folders for the Lawyers court calendars and give access to all the employees to view and modify the calendar items. I know the better way would be to have that information put on the individual personal calendars of the lawyers and then share them that way.
My problem though is not necessarilly public folder issues, it's activesync issues. If a lawyer has a phone with active sync, there is no way other than some third party tool to sync with public folders. If the lawyer had their public calendar as a personal calendar but wanted a second personal calendar for private items, active sync can't sync both calendars only one.
So my two cent is that you do a better job with activesync.