Very enjoyable mission, straight forward main objective with some cool (optional) side objectives. I loved the level design, the mansion isn't too big and rooms have a unique layout or certain objects in them so it's easy to remember where you've already been.
Some OM voice lines are used at the right place to ease gameplay progression further. The amount of guards and placement / patrols was just right for me although I don't do Ghost. Blackjacking ony a certain amount of people is optional, thanks for that.
The loot requirements for Expert are very strict but doable without a walkthrough if you've got the time. The twist at the end was pretty cool, I liked the general atmosphere. If you like mansion missions, this is a must play!