The experience of a cross breed owner from the USA.

I had a cross adopted from the SPCA. She looked just like one of the Spinone crosses I have seen on a UK site. As far as health, she had hip dysplasia, arthritis and needed two ACL surgeries before age 4. She was literally the $40 dog that cost us $4000. She had all the high energy of a Springer but it cost her physically. As far as temperament, she developed what appeared to be "rage syndrome" around age 5 and bit several people. 
I got her when she was about 8 weeks and raised her by hand in our home with our purebred lab.  she was a true family member (slept with us, traveled with us etc.) and dearly loved.  Giving her up was one of the hardest things I've had to do, but it was necessary.  It broke my heart. 
From an altruistic perspective, I would love to adopt an animal who is already on our planet and needs a home.  However, from a practical perspective, I will never add another cross breed to our family.  It is simply too much of a wildcard.  These breeders say the "best of both worlds" but, in my experience, I've seen it can also be the worst of one or both worlds.