I LOVE cocker spaniels, you may notice my profile picture is one. That's my girl, Sophie. She is currently our only dog but we have had 3. Cockers make excellent family dogs in our experience. Sweet, loyal, intelligent, gentle, not very barky, just perfect. My biggest complaint would be as Sophie has aged (she's 9 right now) she has started to shed more. Not enough that it ends up on clothes or the furniture but enough that it does irritate my allergies. I would NEVER get rid of her for this, just something to note. Sophie is the picture of good health, her only problems are acid reflux that is controlled with plain old Pepcid and she has a gluten allergy. But otherwise very healthy.
Our first cocker lived to 11.5. He started to have health issues at 10. Cushing's disease was the biggest problem that led to many more problems. He had thyroid issues, hip dysplasia, tore both his ACLs... I'm forgetting his other problems but the first 10 years were great, the last 1.5 were rough. I'd do it all over again, he was a sweetheart.
We lost our other dog in May, he was only 3. He was actually a cockapoo (half cocker, half poodle). I got the mix because of my allergies. He developed an autoimmune disease called immune mediated thrombocytopenia when he was 1 as a very rare reaction to his rabies vaccine. I'd still (and do!) vaccinate animals because the rewards are worth the very minor risks. Anyhow, He needed immune suppressants from then on to keep his immune system turned off so he didn't bleed to death. In May, he suddenly became paralyzed (poor thing had terrible luck with his health). He had IVDD and we spent a small fortune trying to save him but coupled with his immune system being shut down and the bleeding issues, we lost him. We will be getting another dog, likely another cocker, when we are ready. I just love cockers, their sweet personalities are worth whatever health issues mine have had. Lady from Lady and the Tramp NAILS the cocker personality. They are sweet and protective of their families. I love all dogs but cockers just have my heart.