I currently have no one on ignore. I use it like the mods use Vacation. If someone annoys me they get put on ignore for a short period and then eventually come off. Sometimes they have gotten the boot in the interim, and sometimes I just misinterpretted what they said. Other times they continue to be what they are and I just stay away from them. It seems to work for me. YMMV.
Officer Mitchell, I thought you said you didn't want to have to come back here this evening.
I don't put anyone on ignore. I just ignore them.
I actually use the ignore feature very lightly. The posts still appear; they're just collapsed. It makes them stand out more and actually draws my attention. Just learning to gloss over certain names is easier.