It seems like a good option to be able to make them exempt, but I actually like the idea that membership can give their opinion about moderation, and just let me apologize profusely to anyone I've recently suspended.
One of the things I like about this sites interface over others has been:
a) the dark background / light text format which is easy on the eyes
b) post management: what's a response to what and has it been responded to.
b) the complete lack of gimmicks/noisy graphics.
Message rating doesn't tell me anything much because partisanship is usually a feature of the discussion sites I visit. I've only used the ignore function for kinds of posters who don't feature / continue in an annoying vein ... for long here.
A real boon would be one-click text formatting features built into the reply box. The need to write out dbcodes in 'longhand' being a bit of a drag in this day and age - especially in what is an otherwise slick-as-can-be user interface.