It is certainly is a lot better cruise when they are efficient, friendly, and do their job. I think of all the cruises I've been on there is just one cabin attendant that I recall being a bit unfriendly but did the work just as well as the others. That chap is remembered but didn't affect the cruise at all. I really wouldn't care if I ever saw them if the job was done and I didn't have an issue I needed them for.... but I would miss the interaction. Most are a treat to deal with and I learn a lot by being friendly with them myself.