I have a fantastic helper -- loving to our daughter, reliable, trustworthy, endlessly cheerful and helpful.
She's a godsend. As a working mom, I don't know what I'd do without her.
But I also think it cuts both ways. She's a happy, productive worker because we don't work her like a slave. We don't expect her to shoulder all the childcare and housework herself, and we give her all her legally entitled time off, including all public holidays and FULL Sundays. (She leaves work at 10 pm Saturday and comes back 10 am Monday). We pay decently, and on time, and make sure that she has enough food and basic needs met. We were patient when she first started and made some mistakes -- she's learned now and is excellent.
The people across the hall keep complaining about their terrible luck with helpers -- they've gone through FOUR, which must be a mess with two young children. But their helpers have told mine that they are not given enough food, are forced to work 7 days a week, and are monitored 24 hours a day by camera. No wonder they burn out, and become "bad" helpers who are careless, listless and in a bad mood. I don't think those helper start out "bad" -- they are turned bad by circumstance.
Part of it is luck. But part of it is that you get the helper you deserve. Treat someone well, and they will treat you well back.