There so very few ethical breeders here in Israel, that buying a pedigreed cat is often more trouble than its worth. I have even had ragdolls with aggression problems come for treatment (I do behavior counselling). I think the important thing with purebreds is to buy one that comes from an ethical breeder. An ethical breeder would also supply you with papers, but that is not to say that any breeder that had papers for his cats is also an ethical breeder.
With purebreds, because the genetic pool is relatively small, it's very important that the breeder knows his/her job well. Otherwise you end up with cats that are more prone to health and behavior problems - not less. Again, papers are no proof that the breeder is a good breeder.
Of course, I'm all for rescuing from shelters - mixed breeds or purebreds. The above is just a general warning. People tend to think that with purebreds you get a cat or dog that is in better health and has a more predictable behavior. This is true - but only if the breeder is a good one and not a backyard breeder.
Same reason why you should never breed your purebred cat, even is she is pedigreed (i.e. has papers) unless you're a professional breeder with a good breeding plan.
Just my 2 cents