Brad - the 4000rpm Delta 120mm is only 190cfm according to
this.
Kibbler - to get a relative idea, go
here. They've recording what the various fans sound like. Remember lower RPM fans at the same dBa rating tend to be much less annoying than the high RPM screamers. Remember also, dBa is a log scaled measurement, so a difference of 3 is TWICE as loud.
Haddy - actually that Rotron not only puts out more than the Delta, but is quieter too

Even at 7V it would still put out in the 130CFM range.