We have one, and she is awesome. We only have her come 1x per month though. DH and I are both pretty clean and keep up the house, but hate the little things like dusting all the blinds, washing windows, cleaning the fridge/oven, etc., as well as really deep deep cleaning the bathrooms. She spends 4 hours or so here once per month doing the more involved stuff and really deep cleans. We just keep it up until the next time - light obvious dusting, sweeping, light bathroom cleaning (toilet, wiping down counters, light shower cleaning).
Without a dog anymore, and just being the 2 of us, it works well. Once a kid is thrown in the mix, we'll have her come probably every other week. We pay her $100. I don't know how I found her, but it is an insane deal. Other quotes I got were $200 or so. Nutso.