In reply to manning999:
One advantage we see with using module-based BFMs instead of SV interfaces is that we can capture parameter settings and pass them up to the agent via the configuration database.
I am having trouble picturing why this is the case (that you end up having a parameterized agent). I currently use some parameterized interfaces; I have parameters defined in a test parameters package file, I feed parameters to the SV interface, and my test also has access to these parameters, and can place them into the agent config object(s) (which gets pulled via database by agent during build phase).