YES YES use them if you can afford it--- but YES YES get references.
I have several good friends that are house cleaners. The good ones-- and the trustworthy ones-- get a LOT of steady, repeat business.
Ask for references and *check them*. Personally I'd not consider a cleaner if they could not give me one reference of someone who's been a regular customer for the past five years or so-- and maybe a few more who've been customers for a year or three--- yes this is tough and maybe overboard, but people aren't interested in cleaner-shopping, they will keep the good ones for a long time.
The two I know the most have been cleaning a few of the same houses for 15-20 years. Note, one of them --as she's changed companies a few times, and the customers drop the company and contract whatever company she's moved to.