[regrep] Core Components and XML Serialization - Which Approach?

All,

I've been thinking more about this issue...that is, given a set of
metadata attributes (such as those specified in the Core Components
spec), which should be part of the RIM (through a binding) and which
should be "pushed down" into the contents - i.e. as a "wrapper" for the
core component or associated entity.

For example, lets say we need to provide for the following metadata for
a Core Component (this is all hypothetical):

- Object Type (Basic Core Component (BCC), Basic Business Information
Entity (BBIE), etc.)
- Creation Date

And let's say the Core Component contained "Contact Information" for an
individual. In general, there are 2 approaches to representing this
metadata (let's say for simplicity that you cannot split the metadata up
- that is, you must include all metadata in one approach):

(1) As part of serialization
(2) As part of RIM

Approach #1 would look as follows (note "CoreComponentMetadata" header,
with data in "CoreComponentData" element):

<CoreComponent>
    <CoreComponentMetadata>
       <ObjectType>BCC</ObjectType>
       <CreationDate>2003-01-03</CreationDate>
    </CoreComponentMetadata>
    <CoreComponentData>
       <ContactInformation> 
          <PersonFirstName>Harry</PersonFirstName>
          ...more elements here...
       </ContactInformation> 
   </CoreComponentData>
</CoreComponent>

Approach #2 would look as follows:

- ObjectType and CreationDate are RIM attributes
- Serialization looks as follows (note no "CoreComponentMetadata"
element):

<CoreComponent>
    <CoreComponentData>
       <ContactInformation> 
          <PersonFirstName>Harry</PersonFirstName>
          ...more elements here...
       </ContactInformation> 
   </CoreComponentData>
</CoreComponent>

My question is: What are the distinct advantages and disadvantages to
each of these approaches?  And which previals (if any) as the most
advantageous/preferred approach to representing Core Components and
their associated entities?

Looking forward to some great insight...Thanks!

Joe