I had a full blood male Chessie, and now a female Chessadore and both are, were, good with kids. The male growled and snapped at my 2 year old son when he got close to his food while he was eating. A couple, three, good lumps on his head and it never happened again. The kid could share his food if he wanted too. The dog was very protective though. Nipped my sister one time when she reached for my kid. You couldn't stop him 'til he finished a retrieve. I can't think of a bird I lost with him. My female's 3 and gets better every year. A little hard headed, but tons of drive. Only thing she lacks is a good trainer.
As far as health goes, mutts are typically healthier than full bloods any way. I can't count how many guys on these forums have had to have their 800.00 dogs put down at an early age because of some sort of health issue.