If the CISCO-SYSLOG-MIB is loaded and compiled, can ALL log message be Interpreted by the trap receiver?
I'm afraid some functionality or messages may be lost by taking the SNMP CISCO-SYSLOG-MIB route as opposed to the syslog server route...
All clogMessageGenerated notifications from devices should be properly decoded by the management station. The entire message is encapsulated. Whether or not processing messages using the syslog-to-trap encapsulation is more useful that the syslog itself depends on your management station. I happen to think RME (4.x in any event) does a good job with processing syslog messages and turning them into external actions.
Since the trap breaks out facility and severity into separate varbinds, the trap manager also has a good chance of doing useful thinks with the syslog notifications, but this may require more scripting work on your end.