Hi there
allow me to asure you of the capabilities of CiscoWorks.
Upon a configuration change on a cisco device , it will send a syslog message and/or SNMP trap to the CiscoWorks server. Once CiscoWorks recieves it , it will then send a SNMP getreqeust to the device and download the modified config via tftp. It will store this config being the latest config. You may then view this new configuration through CiscoWorks; you can even click on a view that would show you only the difference between the new and the old config.
So, be asured. It works very well.