My runner ducks aren't necessarily overly loud, but since they are housed very near my living room windows, I can hear them talk a lot more often than the chickens. My chickens seem to quiet down and roost for the night. The duck shelter sounds like they party the night away -- lots of "laughing" by the girls and "mumbling" by the boys, long after I'm ready to go to bed.
Yes, ducks are messier, in that their messes are soggier and in my opinion, much smellier. Don't know that I can estimate how much more time they require. I only have one pen of ducks and I have seven coops of chickens (housing from two to five each), plus a shelter with two geese.
Would post photos if I could, but the duck shelter is a modified chicken tractor that someone built as a 2-foot high, 3-by-10-foot rectangle, sturdily constructed of 2-by-4's. It was covered in chicken wire, which has now been itself covered with hardware cloth. It has two solid doors, one that lifts at one end and one lifts up from a side at the other end. In the winter, I attach tarps to keep the snow and wind out of most of the shelter, but leave plenty of open space for ventilation.
Because ducks don't seem to mind snow, wind or cold (until it gets totally frigid), I think they are easier to keep than chickens in many ways -- except, of course, for their innate messiness.