Cavs are sweet but a lack a personality imo. And you must only buy a puppy from a breeder that health checks the parents, heart, eye and hips.
Cockers are lovely too ( I have one ) quite high energy, lovely in the house, perfect manners with other dogs but needs attention to her coat regularly. She gets clipped every 3 months as she goes swimming everyday and her coat is a nightmare to keep tidy if left long.
Springers ( I've had a show type ) are wonderful dogs. Again very busy dogs that need a good couple of walks a day, lots of running and exploring. Great with other dogs, no aggression and very gentle with children. Lovely family pets.
Wouldn't get a sprocker. Only because I'm not a fan of this crossing pure breeds then calling them silly names.you have no idea what you're going to end up with.
Spaniels tend to be good dogs if bought from a reputable breeder that does all the needed health checks, are socialised and well looked after, who gives her/his puppies to people who will look after them properly.
Think about the grooming needs, the exercise needs and how much company a spaniel must have to be a happy healthy dog before you buy.