Hmmm...let me see if this helps answer your question. As stated in the AppSync 2.1 User and Admin Guide:
AppSync interaction with VSS
Microsoft Volume Shadow Copy Service (VSS) is the infrastructure that enables AppSync
to create application-aware copies.
When it creates a copy, AppSync coordinates with VSS and Exchange to create a shadow
copy. The copy is a point-in-time copy of the volumes that contain the data, logs, and
system files for Exchange databases.
AppSync coordinates with VSS and Exchange to quiesce input-output to the databases
when creating the copy, and then resume the flow of data after the copy has been
created. During a restore, AppSync coordinates with VSS and Exchange to recover the
point-in-time shadow copy.
So, using VSS, you can take your point in time copy and you can restore that point in time copy.
However, sometimes people talk about "any-point-in-time" (APiT) and get that confused with just point-in-time.
The same doc referenced above talks about
Restoring logs from crash-consistent (APiT) copy
and there are manual steps on restore than can be done for that.
Check out the doc to see if that helps you answer your customer's questions.
I looked into this and I believe that Itempoint was dropped from EMC's product line because Exchange 2010/13 first have the resilience due to DAG and you can also enable 'deleted item retention' which pretty much covers what you would have done with Appsync and Itempoint.
Thanks for the response!