Unless you are making excellent money, yourself, it is more cost effective to do it yourself. Furthermore, most maid services today hire the cheapest illegal aliens (mostly from a country south of California, Arizona, New Mexico, and Texas) they can find. The maids cannot speak English, have no concept of proper cleaning procedures, and pass on information about your valuables to their boyfriends.
Now, if you do have the coin, seek out an agency that has bonded, English speaking maids and/or handymen, who have been trained and don't bring in filth on their tools, from previous jobs.
Remember, any idiot illiterate thinks they can clean. Wrong! If you want a good job, you are going to have to pay good money for it.