OK, so I pulled up the new map and ran around it and flew around it and turned on the FPS counter and experimented with mat_wireframe and uh, there are a few things I think could improve performance in some places, particularly where there's a lot of stuff still being rendered but not actually visible:
ONE: Seal your roofs with nodraw or something. Those areaportals you have stretched across the ceilings of the buildings aren't doing much, especially in the spawn building. Anything high up is still rendering when it shouldn't, particularly the props that form the outsides of the roofs. Which also means, you guessed it, the
inside trim props are also visible from the
outside, even from miles away. There should be enough room between them for a sliver of invisible brushwork. It might wreak havoc on the visleaf generation, but that should be preventable by surrounding the roof with a hint brush.
TWO: Your talk of "aggressive" LOD work made me assume that the roof props reduce to flat surfaces with painted-on AO at great distances. I was wrong. You really need to do this, even if you have to create an additional texture for each skin to make it work. I assume Source lets you set a custom distance for each LOD; even 2048, where players literally wouldn't be able to tell the difference at a glance, would be reasonable because of how much far away stuff is visible at any given time.
THREE: Fade distances. We need more of them. There's no reason some of these props need to be rendering from all the way on the other side of the map. I think you overestimate how much of your map is actually visible at one time from ground level or even the roofs they can stand on (except at mid). And people aren't going to notice a few missing trees when they're rocket jumping.
I realize that none of these are going to have a huge impact on performance in the worst spot, the upper floor of the far middle building facing the CP pagoda. But they should dramatically improve framerates in and around spawns at least.
And on a more minor note:
This rock needs a big ol' occluder brush inside it.