I'm a bit torn apart by this one.
On one hand the mission author made a great job at creating an intriguingly interconnected map. The focus is definitely on the mansion, but you've got some interesting ways to enter that - at the same time it's very easy to accidentally get lost and miss meeting your associate (strangely this objective is described in a useful way only before the mission starts), which can typically be a problem if this is your first time playing the mission.
On the other hand - and maybe it's just me, but - I need to mention that I think this mission is... perhaps not that interesting. Very well built, but I barely experienced anything here I hadn't seen already in dozens of other missions. Yes, there are some fun details (I liked the attic above the mansion, or the pagan cavern a lot, etc), but I somehow couldn't help, but thought something was missing. Again: maybe it's just me, and of course, if you don't get easily bothered by such things and you're looking for a good mansion challenge, go no further!