To be honest I've just begun to use this forum option after five years so it goes to show that there are not many people on this forum that really tick me off. My only disappointment with it is that it only ignores the person's posts. What I would like to see is an option, selectable of course, that if the person is on your ignore list that any threads created by said person are also ignored in their entirety. This would also include all posts by other people even if they are not on your ignore list.
While I know this is a bit harsh and/or extreme, there is one person on these forums that annoys the bejebis out of me and he or she has diarrhea of the brain when it comes to posting threads. I would love it if the devs/mods would limit certain people from continually posting but this I feel would be too cumbersome, very subjective, and have the same flaws the the forum reputation system has.
Adding the above option to the ignore functionality allows me to enjoy the forums more and limits my knee jerk reaction to posting anything that might draw moderator attention or "love letters".