We do a lot of "Military March out" cleans and the standard expected is EXTREMELY high, if they find one hair in the bathroom it will fail the inspection. Taps are stripped down on all march out cleans and scrubbed and polished, door and window recesses are vacuumed out and wet cleaned, cookers are pulled out and cleaned, as is the floor and walls areas where the cooker has been sitting.
It will take two people going flat out a minimum of 4 hours to do a march out clean on an empty 3 bedrom property properly, and that does not include the deep clean of the cooker or deep clean of the carpets.
One of my pet hates, and the people who work for me know it, is limescale and scum build up on the underside of the tap and around the base. So even on our daily office cleaning I ensure things like this are done weekly, they have a stock of small nylon and wire brushes for just these tasks.
My other pet hate is runs down the outside of the sink.
Once you have your staff in the right mindset and they know the standards expected then it is plain sailing and the customer is always impressed with the level of clean, which in turn results in a happy customer who will recommend you to their friends.
If I was a landlord and there was traces of limescale visible, I would expect it to be removed, especially if it was a high priced clean