What exactly do you need to know?
I am not an expert, know an active breeder, and like the breed. They are lazy and at times, slobberly. I think eye problems, eye lid problems are a concern. They are rare, but not super rare in the US if compared to all rare breeds. In September of 2008, 20 dogs and 5 litters were registered--making them the 6th rarest Sporting breed for that month. So, not many people notice them or are looking for puppies.
If you are going to show them, they are harder to keep clean, and with the floppy ears, there is that whole thing to look for. As far as temperaments, they are great, and frisky as puppies. I like the breed.
http://www.clumbers.org/index.php