Yes, they are designer mutts, but it's not about "cute puppies". All puppies are cute, even chihuahuas. What you're paying for is the cross-breeding for certain traits.
Apollo is a designer mutt - Schnoodle: half poodle, half schnauzer. He is exactly what I wanted in a dog. The good news is that he fell into my lap, but I did check out the pups at Callaway Kennels when I was half-heartedly searching. Neither the pups nor the facility was dirty.
Of course I can't find it now, but I read a great article on designer mutts and how they're actually better dogs than pure breeds. Think about it: a pure breed is almost certainly inbred throughout the years, and they are more prone to defects and genetic problems. A mixed dog does not have those issues, and with a breeder you know exactly what the mix is instead of what the shelter is guessing at.
Not necessarily standing up for CK, but there are definite advantages of a mixed breed over a pure breed.