This map feels like a slight step back from map04. It's also large and technically proficient in its construction (though the blue key room had some strange alignment issues). The structure of the level as a whole, however, is less interesting. Firstly, it's a hub-spoke map, which is a pretty linear and uninteresting structure at the best of times, and doubly-so when it's the bog standard "no key, 1st key, 2nd key, 3rd key" approach. The map adds the wrinkle that you have to do the 2nd key wing twice to get the 3rd key, but that's not an especially interesting wrinkle to add.
The map also suffers because the final fight is entirely skippable on difficulties below UV (on UV, the mastermind might make a run to the exit less appealing!).
These weaknesses of the map are a shame, because it has some nice architecture, interesting textures (I like the grimy crates), and challenging fights (the first run through the red key wing being the highlight IMO).
I imagine this would be pretty tough on pistol start, especially on UV. There are quite a number of PEs about the place, and UV has a lot of extra barons, which are real ammo sinks. You do get a berserk or three though, which will help.
Ten secrets on the map; I found only one, but it was the one to find: the BFG :)
Well actually, I found two, but the second one I got when I was doing some random exploring in nukage, and I couldn't be bothered to go get it when I went back to finishing the level (it was a long trek to get a rad suit, and the reward was only a box of bullets).
A decent map, but not quite at the level of 04.