They are very helpful when moving in and everything seems so smooth and easy. When leaving however, the service is not good. Our apartment where we had been for 2 years (without anything serious going wrong) was deemed to need a professional clean after leaving. Without any choice I am still waiting after 1 month to find out the cost that will be deducted from the Deposit, which obviously I have not received yet. Also, our mistake but they simply give your an inventory in the office and tell you to check it. I did not mention to them that some things were missing but on leaving, they will bill you for everything from one fork to a light bulb not working. So my advice, check the inventory, send it back to them noting everything. If you think the apartment needs a clean let them know straight away.
Perhaps this is the same everywhere, but great when you move in, but terrible when you leave.