I have both ducks and chickens.
I have chickens because for eating, I don't like the yolk in duck eggs. For baking, not a problem, but I'm not a fan of yolk to begin with, so the larger and stronger yolk of ducks is not to my taste.
Chickens are easier and cleaner, but ducks are way more enjoyable for me. I do like having a mixed flock though. I much more enjoy ducklings - I've now raised 2 small batches of chicks and both DH and I think the ducklings are always more interesting.
I had a very friendly runner duck - she died after an injury. She was my lead duck. That left me with a friendly duck and a "I'll eat from your hand, but don't you dare try to pick me up" duck. The leave me alone duck took charge.
I then added 3 more ducks and those 2 runners are still very skittish. The welsh harlequin raised with them is friendly, but timid.
Difference... I had a lot of time to spend with batch 1 as I wasn't working at the time. Batch 2 I was working and didn't have all day to hang with the ducklings.
If i have to pick up a bird, my chicken is easy peasy. She may not enjoy it, but she lets you pick her up no problem.
I can pick up the "leave me alone duck" but have to plan it. I can pick up my WH because she is bigger and slower. I don't try to grab the other 2 runners. One was limping for a couple of days and I finally had to corner her with my DH so we could check her out. Not a fun experience for any of us. And she distrusted me for weeks after.
Everybody follows me when I have food.
Noise - I'd say lately, my chicken is louder, especially in the am. But for the most part, any noise ends quickly. My ducks quieted down after their first summer. But if they have something to say, they let the neighborhood know!
Ducks will be much happier if they have water to play in.
My chicken puts herself to bed every night. The ducks... they mostly do, but that took training (walking them to bed every night and providing peas). Now they stand in front of the back steps and wait at dusk for me to come out with peas. If I'm late, the chicken goes to bed... the ducks hang out a while longer and either hop in the pool or quack until I know they are waiting :lol
If we aren't home, they do put themselves to bed. It is only when they know we are home that they hang out and wait.
Friendliness will do a lot with how they are raised.
I had a very friendly runner duck and still have 2 that fit the breed normal "skittish"
If you can spend a lot of time with them, then you will likely have much friendlier birds.
Noise - will also slightly depend on the duck breed - but will be more the personality of the duck.
I had a mallard - she was nicknamed "loudmouth" all she did was talk! Sweet girl, but loud as all get out and often. She unfortunately wasn't around long enough to see if the noise decreased after that first summer :(
Good luck deciding