Thank you, Invincible for taking the time to explain this!
Upon using the link you provided, I must admit that I'm drawn toward the Cavalier King Charles spaniel - they're BEAUTIFUL! It would seem, however that when you have a dog that's been pedigreed so long that health issues arise - this particular dog has mitral valve predisposition alongside another malady called Syringomyelia.
It would be terrible to bond with a dog only to see it suffering with maladies that curtail its enjoyment of life. Very expen$ive as well.