Thanks for your responses and all your awesome work. I'm just coming back to the game this year after not playing since 2009! And it is just sooooo good!
end user experience of having to monthly fill out a preference list
It could be non mandatory and the effect of the preference list could just be a minor weight against the existing algo, like %30 or something. So the user experience would the same for noobs and anyone that is just happy with any map.
I personally would like a 1on1/4on4 random map only ladder. I think that was tested for one week and was a success as far as I can remember.
I love this idea!