I had fun with this mission, nothing in here that was really annoying or tedious.
My main problem with this one is the size of the mission, while it does give a great sense of scale, there's not that much variety in it.
One example would be the numerous bedrooms that look exactly the same, partly with inhabitants and partly without.
Some other parts feel copy/pasted as well like the existence of water arrow in almost every source of water.
While this review sounds pretty negative, I can still recommend it, just don't expect anything mindblowing.
It's a straight forward mansion burglary mission that is too large for its own good but the gameplay (guard placement, patrols, exploration) is still worth the time.