It only took me a few hours total, which should be proof of how easy it is to make something like this with Hammer and the new version of the setup editor. Originally I was just going to make a multiplayer setup for it but I instantly got an idea for a solo mission while walking through it, so I'm going to start on that as soon as I'm done typing this post. The map, as you can see in the screenshots, has two floors, offices on one floor and the rooftop. It's kind of small so my mission will be really short, I think it'll make a great multiplayer level as well.
Update: Here are some screenshots from the mission.