Hi ajlynco. Just from reading the forum and the responses you've gotten you can see some breeds do slow down in winter. I have Khaki Campbells, however, and they do not seem to slow down at all. They have just reached 22 weeks old and each few days another of the girls begins to lay. I have 8 girls and the past 3 days Ive gotten 5 eggs per day in the nestboxes when I let them out in their run in the morning. I live in Illinois where the days are already short and weve already had a few hard freezes and I do not provide any artificial light. So I think its safe to assume they will lay year round.
As for the differences with raising chickens. For me the biggest difference has been the muddy mess that the ducks make. I think pound for pound they may be messier than pigs. As Duckgirl said, you want to give them at least a kiddy pool or something to splash about in but whew will they make a mess with it and even with just their waterer. If possible and you can put their water on rocks or sand rather than dirt, you will save yourself alot of headache. Also they do not need roosts, but mine do use the 16" x 16" nestboxes i made with plywood and filled with straw.
Oh yeah and the eggs are way better than chicken eggs! Bigger, thicker, and richer! We fry them every morning and the yolks are always creamy never runny and even the whites have a lighter texture than chicken eggs. My wife was sceptical at first about eating duck eggs but now she already brags to everyone about how much better they are. Delish!