I prefer 有經驗的, because It's very very hard and tired to train and teach if she is no experience. Also, I will be very scary everyday, specially when I'm not at home.
"打BB" - It depends on she like baby or not.
"太精" - It depends on her own.
if no body is at home, I prefer one with experience. However, my mother-in-law is at home and can teach a blend new maid. Experience maid will not like to follow your instructions and always has their working style.