One thing I'd like to see is limiting the votation to only maps that have not been played in the last 2 map changes, i.e. if the server just played badwater and is currently on goldrush; badwater wouldn't be available until 1 more map is played and goldrush wouldn't be available until 2 more maps are played.
Just something I've noticed as lately the rotation ends up being a mix of Badwater/Goldrush/Upwards. Frontier, Beerbowl, Cashworks, Everest (version 4 IIRC), Hoodoo are all good maps that need more rotation and play, IMO.