Scovies sure are sweethearts, despite having a face only a mother could love! Quiet, too. The only problem is they're huge, and have big ol' sharp claws that could really hurt a kid if they tried to pick one up. I swear, they have the legs of a dinosaur...
I think the keywords here are "spent many many hours with" and "labor intensive". :p Like I said, I'm not saying that runners always have to be skittish, that's just one of the stereotypical characteristics of the breed, is all.
Besides, no matter what type of duck the OP wants to get, it's...
I do love me some cayugas! Runners aren't good for kids, in my opinion. They can be skittish and tend to prefer hanging out on their own, they're not that snuggly or social (although obviously there are exceptions to this).
A more important question though is, are you sure you're ready? Ducks...