I am a man that lives alone, so having to clean the house on my own would be a nightmare. I love the convenience of not doing anything (except paying :)) and getting my home cleaned professionally.
Major positives: extremely convenient and overall great service. Love the feeling of coming home to a nicely cleaned house. I also enjoy the fact that they change the bedsheets with fresh ones - I hate doing it myself so this is another weight off my shoulders. I like the fact that they report anything damaged and have been able to discuss it with the managers and have it reimbursed within reason. This keeps my mind at ease especially having strangers in my house. The fact that the workers are fully bonded and insured is a big plus.
Some recommendations: Because of the speed required to go through a home cleaning, a lot of my personal items are not placed back in the same spot after being moved. It takes me 15-20 minutes when I get home to get my stuff back where it should be (I need my things in order). While I understand that doing this will take time away from a more thorough cleaning, I do prefer that my personal items will be approximately in the same spot (give or take - I don't have OCD). Occasionally some spots remain untouched, again because of the speed, but that is more rare and hasn't really bothered me too much.
Recommendation: Generally I have been very open to recommending merry maids. The main pushback I get from my friends/family is that they are still set on the old school private lady that comes in and cleans the house. Their argument is that they are cheaper (cash pay) and they take their time to go really thoroughly through the entire house. Individual private ladies have their own drawbacks, including slow service (most of them take much much longer, effectively bugging you with their presence), are not bonded and insured, and have generally not cared much if they broke anything ("was already broken"). I recommend Merry Maids to anyone because I am very pleased with the service.