The module has some quirks inherent in the way Cybersource requires things to work. The module physically works well, with the caveat of no echecks yet, and is easy to use with the rest of the BOP framework, as long as you setup Cybersource correctly. They are designed for larger companies, for sure, and don't act the same as the other backends, but they also provide the best Error codes (which this module provides access to) of any of the merchant accounts.
I wish I could rate the service, but we were never able to get it to work. Our entire online payment system was offline for six weeks while we called and called to get help to no avail. Finally we had to switch to a competitor's system and it was working the same day.
Not only did Cybersource stick us with signup fees, but they charged exorbitant fees for canceling the two year contract as well, even though it didn't work!
Do yourself a favor and try another online payment solution.