[PROPOSAL] PersistentFactory performance improvement

All,

We have seen that in certain situations the Persistent factory (PF) 
components, for both default persistence and Hibernate, are being 
created many, many times.  These are heavyweight components, with a 
large penalty in CPU time and memory, whenever instantiated.  Currently, 
these are pooled components, but even so, too many are being created.  
The proposal is to modify these two components to become singletons, as 
they originally were before securable persistents came to be. 

The downside of it is that this requires an  API change.  Currently, to 
check authorization, the PFs keep a copy of the user context (or, 
session, in Hibernate).  However, this makes it not possible for the PF 
to be a singleton, since you need a copy per user.  Instead, we can 
supply the context whenever a securable persistent needs to be created.  
In other words, we currently do:

Persistent p = pf.create("myschema.mypersistent");
Persistent p = pf.create("myschema.mypersistent", transaction);

Instead, we will do:

Persistent p = pf.create("myschema.mypersistent", context);
Persistent p = pf.create("myschema.mypersistent", transaction, context);

This will change users' current code, but only if secured persistents 
are being used.  For "regular" persistents, the old API will still work.

The huge performance and memory usage gains are likely worth the 
backwards-incompatible API change, but feedback appreciated on if this 
is palatable to all who will be affected by the change!

Shash