Experiences on dampening

Hey all, attempting to assess something related to networking but its on the SIP/telephony side of things. I'd like to know how many have had success and failures with route dampening. Purpose of this question is, I'm wondering about a method a VoIP PBX could take similar to BGP's dampening where the following would occur:

SIPUSER REGISTER (SEND SIPINFO + IP_INFO) --> Server

If SIPUSER decides to either REGISTER, INVITE, SUBSCRIBE, etc., in an insane amount of time, VoIP PBX would take action on it. Give SIPUSER an initial penalty and increment it justly however, it *cannot* be address based. It would likely be two predefined variables. Overall I just would like to know experiences, pros and cons, with dampening.

Thanks in advanced.