Well, I've got all of architecture in place now as well as a finalized the main route through the level (as well as plenty of shortcuts possible for those skilled enough ;). Today I've been going through the level trying to better balance the ammo/health/armour/monsters for the hard skill setting. It's all looking pretty good and I'm tweaking the lighting and other details as I go.
The current brush count stands is about 4700 and with 4 hour compile times, a lot of guesswork is involved working out the item/difficulty balance between compiles. While building the map, I even had to compile a special version of TyrLite to handle the huge number of planes and surfaces in the map.
All being well, I'll be looking at sending out a beta (of the map) to a couple of people this week. Oh, and please don't ask for the beta, I already have some people in mind. If I need more testers, I'll let you know.