Proportional representation based on race or ethnicity is a profoundly evil idea to me, that makes my skin crawl.
How about based on party?
I don't know that I like the system it inevitably creates. Multiple parties to represent the different parts of society rather than two big tent parties is obviously a huge plus. The downsides are twofold; a political system prone to huge swings, exacerbating rather than moderating economic or societal problems (as can be seen, for example, in Greece) and an inevitable strict party line, meaning all independent voices in government are shut out.