Outlook free/busy lookup: local replica vs. user's default PF

Hi,

We are getting confused how free/busy lookup works in Exchange deployment
with multiple AGs. If the Exchange server I am connecting to with Outlook has
local replica of Free/Busy folder from another AG, and I am trying to lookup
free/busy for user from that AG, will Outlook use local replica, or it will
still go to user's default public folder store first?

According to the following article, local replica is preferred over
everything else, this is what I would do if I were Exchange architect so it
makes perfect sense to me.
http://www.microsoft.com/technet/pr...2.mspx?mfr=true
Some other article with Microsoft recommendation of free/busy design also
recommend placing local replicas with data from other AG for faster and more
reliable access to the data.

However our customer did some tests and they claim that local replica is
used only if user's default public folder store is unavailable. And if that
server/store IS available, local replica NEVER used. They also claim that
some people from Microsoft have confirmed it.

Could someone shed a light on this?