I've never hired a maid in TS4. I always have a handy sim in every house, and make everything self-cleaning if the option is there. I've yet to hire a butler.
Nannies, though, are a different thing. The one time I had one, kind of put me off the idea. All she did was watch TV and dance to the stereo. Found out she was a Dance Machine, go figure. I ended up actually moving her in, like she was the childrens grandmother. Worked out pretty well. Especially since I found Daycare to be worse, with never taking care of the little ones needs.