I've not had much experience with ducks, but I'll tell you what I've gathered so far. I got 1 Khaki Campbell and 1 black and white Magpie from Ideal Poultry a week ago. (They are not the best place for waterfowl, but mine are fine. I'm not breeding them or anything so they are fine.) They were one week old yesterday.
The things I have noticed about the Khaki:
1) She doesn't like swimming as much as the Magpie. She prefers the submerge her head to clean it, paddle around for a minute, then get out.
2) She's a bit more skittish than the Magpie, but she still likes me. Especially when I bring peas!
3) She's a bit bossy. She tries to lead the Magpie around.
4)She LOVES to climb! She tries to climb on me as high as she can. She is always trying to get to a higher point than she already is. She's a little mountain duck. 
		
		
	
	
 
Things I've noticed about the Magpie:
1) She LOVES to swim! She will dive and paddle and play. But when she's done, she's done. She will hop right out of the sink on to the counter and wait to be dried off. 
2) She's friendly. She likes to be held. She doesn't like to be picked up, but once you have her she likes to cuddle up with you. She will let me pet her more readily than the Khaki will.
3) She will try to eat anything! Especially shiny things. I just got a new ear piercing and she hopped right up on my shoulder and tried to eat my earring. Which hurt really bad. She nibbles on my hair, nose, eyes, ears, eyebrows, fingers, anything. She doesn't care. She's not rough, just curious. It's adorable to watch her explore. 
 
They weren't really bonding with me until I started hand feeding them peas. I'm pretty sure they would do a backflip for peas. They go absolutely nuts or them. Now they follow me around and sit in my lap. They either consider me Mama or the Pea-Bearer. I'm not sure which. 
Overall I prefer the Magpie's temperament so far.