Had about an hour on this earlier, am sneaking my way through the Highland Park facility (taking everyone/most of them out) and enjoying it very much! Got up to the two FEMA workers who question who I am.
So many ways to approach a room/area, it's so much fun!
(although I do get a bit confused with all these organisations)
Realising there'll be my first proper boss at the end of the level, and having only bought my stealth weapons to the level, I've been trying to gather machine gun ammo where I can from the guards :p