"King Charles Spaniels have very good temperaments. Never known a snappy one. Do shed a lot of hair though, are prone to ill health, and will eat you out of house and home. Quite dull too."
Now, do you mean King Charles, or Cavalier King Charles??
They are different breeds, and you probably mean Cavalier King Charles, as they are the more commonly found breed. These are LOVELY dogs with children, and not in the least bit dull . We have 2, they are very sparky, playful dogs, super temperaments, never ever snap. They love attention, even toddler type attention, and one of mine adores being dressed up in bonnets and pushed about in a pram !!! They CAN walk for miles, and love being out in the open air, but don't need much exercise if you don't have lots of time (and don't overfeed).
They don't eat much at all (well they shouldn't. You have to stop them learning greediness in puppyhood)
Cavvies do havea reputation for health issues. You need to find a good reputable beeder, and ask lots of questions about the parents. But they are THE best breed with small children, I'm sure.
King Charles are slightly bigger. They don't have the same health issues (not so interbred), and tend to be less out-going that Cavaliers, but still lovely dogs. Again, shouldn't eat much, they are only small dogs.
Harder to find as a pup tho'
Both breeds can grow long coats, and would need loads of grooming UNLESS you do as I do, and have them clipped 3 times a year.