I have used this feature, and it has helped. I too had a network outage, mine due to a "developer's" platform ARPing the MSFC on the 6000 as fast as it could. The MSFC's CPU went right to 100% and the network slowed to a crawl.
I set the broadcast suppression to 1% on my 100Mbps links to wiring closets. This allows no more than 1Mpbs of broadcast to get through. In one case, this was still more than a small router could handle (millions of frames were filtered), but, the MSFC hasn't had an issue, and that's what was really important.
