Well, the theoretical security hat that we wear tells us to avoid a class break by using different passwords on different machines. The pragmatic network manager, who barely has any time to even put on that hat, says we should create a Credential Profile with a username and password for SNMP and then apply that to several nodes. It's probably easiest to stay in the middle of the road with a few different credential profiles assigned to different node groups whose passwords you change according to your security practices.
