I have a Cockerdor that came from a friend of a friend, who had his half-brother, a full spaniel. Breeder's is a family home, they have a couple of Cockerdors themselves from an earlier bitch being an escape artist; this litter was deliberate, bred to a Lab who lives on a farm nearby. Both parents live as pets. Breeder's dogs live in the house and I was very confident that the puppies were well-raised.
I know lots of people are very insistent on pure-breds and kennel club registration, and I can completely see why, but I think there's probably some space for the occasional mix if you are absolutely certain about the ethics of the breeder, the character of the parents, and the upbringing of the litter. I suspect that won't often be the case with mixes. Go visit at the very least.
Bottom line is that a first generation cross is completely unpredictable, and you need to know you'd be happy with however the dog turned out. He could be a great mix of all the best traits of both breeds, but equally could have all the pain in the arse traits of both - I'm told GRs can be mental until they're about two years old, many cockers are permanently bonkers. My boy looks like a short-arse Lab, with a beautiful glossy short coat, which in one way would tick your boxes, but the downside of that is that he has the strength of a Labrador with a WCS's desire to stick his nose on the ground and pull. Imagine that with a GR, shedding like a giant stinky dandelion.
My boy is the love of my life and I wouldn't swap him for anything. But it could have been very different, and if I had another dog I'd seriously be looking at the kind of breeder that has a waiting list.
Picture of his gorgeous self.