Tony I will voice my opinion and take it for what it is worth.
Do not waste your money. They are not accurate. You will get cross linking and if the electrician did not unwrap a multi cable wire that shares the same neutral you will get cross linking.
If you really want to lay out your house circuit wise. Borrow the kids, grand kids or the wife. You can also do it yourself. Alot of walking in a mansion like your though.:biggrin:In a house there are not that many circuits unless someone was annal and split the heck out of the rooms. What you do is shut off one breaker at a time. Go around and find that circuit with a good circuit tester. Those cube testers are very good for this. It has lights to show visual and some even have sound. Usually the whole room outlets are on the same circuit so you will do this quickly. After you found outlets and or lights, remove the cover and write on the back in marker the circuit number on each device. In commercial work they use those PTouch machines because most places this is now code. But they put them on the outside of the covers. I do not think you want that in your house. Also now mark the panel in plain good direction language. If you have to make a separate card other than the one supplied do not be afraid to do so. Make sure it is placed in the panel door some how.
This is what I have in my house and what I do if doing work in someone's house. I mark the heck out of what device I am working on both at the device and back at the panel. Does not take long and you do it once. Then those devices are not needed any more. If you have work done in the house make sure things are marked properly. This is just my opinion.
Now I have used very sophisticated circuit finders in computer rooms because you can not shut off breakers at will. They are not home owner equipment though. Good luck.
I am sure there will be someone will say what happens when you paint a room and take all the plates off??? Mark the outlet or the box. There is always a place where the plate covers that you can mark.