It comes up alot, for example this morning, I went through several spam collections & realized we are getting quite a bit of spam from ".best" & ".monster", so I am blocking these via Postfix's check_sender_access. If all spam was on one page, I could get to this conclusion quite a bit quicker.
There are other ways to get at this information, however the quarantine page is well designed, it would be nice if I could use that instead of rolling my own thing.