You just want to make sure you have your "message-based" CCS Mgr on it's own box (no other CCS roles, not even other data collection roles).
Why? We throttle it down for msg-based Data Collection. (and that's "real world") See the v11 planning & deployment guide, page 93. This is from page 94:
"
Using a CCS Manager with Collector role for message based data collection, with
other roles such as evaluation or reporting may affect the data collection
performance. Symantec recommends that you install a CCS Manager only with
the Data Collector role for message based data collection.
Using a CCS Manager configured with above mentioned settings to collect
agent-less or agent-based raw-data may affect the data collection performance.
Symantec recommends to use separate CCS Manager for agent-less or agent-based
raw-data collection and configure routing rules to route the assets to specific CCS
Managers.
"
Hope this helps! :)