I have a friend with 3 Springers and 2 cockers. His Springers are fab, were easy to train, very obedient but very needy - they are used to seeing 'dad' when they are working, so don't relax if he is out of sight. All 3 are great with kids (ignore them) and are pretty bomb proof. They need a lot of exercise, but are happiest rooting through the woods. Two have really soft mouths, soft hold but the one is a killer.
The cockers took much longer to train and are more 'skittish'. They are nervous around children. Not sure, but to me they don't seem as clever? They are more loving than the Springers and more food centric. They don't retrieve very well (even though they've had the same owner, same training). As a pet their size is probably better for kids, but they aren't great workers.
But it's all academic really. It's down to the dog, not the breed. I have a Mutt, she's probably Sprollie, but there seems to be something else there as well. She is fab with DD, but wary of other kids until properly introduced. She is skittish and growly with strange noises and strangers but soft as hell. She is submissive with other dogs, flat on her back, but hates strange dogs going near DD and is very protective. She was easily trained, is great on a lead, loves to retrieve (balls) but is scared of pheasants!
I suppose what I am saying is that you cannot generalise. Whatever dog you choose there will be good and bad sides to it - I believe dogs are mainly what you make them with a little nature thrown in. Yes Springers are 'known' for being crackers - but my friends 3 aren't.
Don't set your hopes on a certain type of dog, you could be disappointed.