I have never used a Rainbow, but they look like a wonderful machine and I too would love to purchase one. However, they do appear to be a machine that does require a little bit of extra care in order to keep them running their best for many years. While I have no doubt that a Rainbow can probably handle some of the abuse of a maid, I dont think this is the ideal machine to have the maid use. We have had several housekeepers over the past 15+ years and while the last one was absolutely the best around, I dont think she would have been to keen using a Rainbow. Maria, was the housekeeper that came with stellar references and she was the one that had a waiting list of future clients. If you have a live-in housekeeper I think it might be a different story, but for someone that cleans more than one home a day, this would add to the time they spend in your home. This would hamper their ability to quickly move through your house and on to the next one. We have had Electrolux canisters for years, and every housekeeper we have ever had have told us most of their other clients had Electrolux canisters too. I think a high end bagged canister might be the better choice as it gives your maid the ability to pull it out of the closet, plug it in and vacuum away, then put it back in the cloest as soon as they are done.
One other option is to install a central vacuum system. When I installed one in the house at the time my family and the housekeeper were using a Miele Blue Moon and Red Velvet. When Maria found out that I put a central vac in she was so happy. She liked all the previous machines that I had, but the central vac she was just head over heals about. A nice unit can be purchased and installed, along with the right accessories for your own home for probably around the same price of a new Rainbow, plus it can add to the value of your home.