I have three cats; Socrates (Socs), Cassanova (Cass), Aristotle (Ares).
I love cats and have always had a pet cat growing up. They are the animal type I most understand and appreciate. I know all of a cat's nutritional, environmental, and behavioral needs which makes for 3 happy, healthy, and well behaved cats. I've never had any regrets or issues with my three boys. I understand why they act a certain way and through that I'm able to fix any issues they may have. Most cat problems can be fixed by either playing till the cat tires themselves out or adding another litterbox so they can mark in an area where they're feeling less secure.
Grain-free raw food diet has done wonders for my cats. Cats, in general, aren't meant to eat or digest grains. It's ridiculous how it's in most store bought cat food brands. Instantly, their coats grew fuller and softer and they all have crazy high energy levels. Playtime gets pretty crazy fun in my house. 
Hmmm, your questions are a bit odd to me. Expectations? Disappointed? Holding me back? Money's worth?
None, of these are thoughts that enter my mind. I don't see them as objects I bought from a store. They are beings that are apart of my family, good or bad, healthy or sick, they are my responsibility to take care of no matter what my expectations are. When I adopt a pet, it's because there's an empty void in my home. I adopted Socs and Cass, because my previous cat Zorro passed away and the house was so empty and lifeless without that spirit around. There's a completeness when an animal is around. I also adopt to save the animal's life in the shelter.
To tell the truth, all three of my cats lied to me the day I first met them. Socs was super chill and feel asleep in my husbands arms, only to later find out he was just super sick with kennel cough at the Humane's Society and near close to death. Cass was also super sweet and loved everything, he even did a super special kitty dance when we first met (we were meant to be together), only to find out he didn't particularity want to live with other cats. (that was fixed later on through slow pleasant introductions and positive reinforcement) And Ares (the god of war) was a sweet 6 week old kitten I rescued after watching a lady dropped in the bushes outside of Burger King. He became apart of our family because the Humane's Society wouldn't accept a stray and Animal Control would have killed him. (Ares mellowed out also through positive reinforcement training and neutering)
Adopting a pet requires learning and researching before hand. It's a commitment. Even with Ares, where I didn't know what we were getting into and adopting him was thrown in our laps, I decide to commit to any baggage he may bring with him. I find it quite distasteful when owners surrender a pet because they weren't prepared for what they were getting into. That's not the animals fault, it's solely the human's. We're their guardians, not their owners. It's important that we make the best lives we can for them.