Well they are birds so they can make a mess however if you limit yourself to two (they are social and should have a companion) it's not bad at all.
I clean their coop once a week, monitor their water daily when checking for eggs, re-fill food once a week as well and that's about it.
Having the waterer and feeder suspended help reduce the mess and amount of cleaning.
They can make great pets and the bonus is that you have fresh eggs each day.