The "Compatibility" vote option is a great thing. After using it, I've one suggestion : allow poster to remove it's vote.
I noticed that it's possible to change a vote from "works" to "Broken" (and vice-versa). That's great! However, in some corner cases, would be great to be able to retract a vote. Here is an example why:
I voted by mistake for the wrong plugin: I had 2 plugin pages open for same functionality, downloaded/tested one, and voted on the other one page :-( Sure, I should be more careful, but now I can't correct my vote (I've not tested the other plugin).