I really don't know if I can put down what makes Strogg architecture. I'd say that the architecture is more centered around level design, but there is something there. I feel like that there are hallways that connect to rooms, with occasionally "outside" portions where you can see the sky. Play singleplayer QII for a while, and see what you find. 

Quake 4 had a pretty good blend of Q2 architecture with its own modern areas. 

I feel like that there are hallways that connect to rooms, with occasionally "outside" portions where you can see the sky.

Cool insights bruh. Also sometimes when playing I get the impression that there are doors occasionally, and also floors, and sometimes ceilings (but not always?). Walls often feature too, but I assume that's more because of tech limitations (without walls you would see the whole level at once and that might cause the multiplayer to lag) 

As PepeLord86 is stating, what I said is very obvious. Hallways and rooms are pretty much nature in any map. 

The base map I'm making is very Strogg in terms of architecture. It seems like a good fit for speedy base. 

repeating blocky shapes, massive angled structures, pompous entrances, random blocky angles, huge simple surfaces, pseudo-sacral elements, random rounded shapes thrown in with angular stuff, areas built around obscure pseudo-technological structures.

I don't see too much Quake 2 in Quake 4, it's mostly the faceless ribbed facades that resemble some areas from Quake2's first couple levels. The weird stuff from later levels is largely absent in Q4, especially the things that could be understood as sacral elements - some sort of cult of the machine. This was visible in some Q2 textures and the palace-type levels later on. It is something that Q2 had in trace elements and that for example the Borg from Star Trek have always had as well (they like blocky gemetric forms too.) The machines basically represent the dead, or the afterlife, or something. Somewhat like zombies, only creepier.

Quake 4 missed its chances there. 

 

Sacral elements? I don't recall seeing anything like that (and Quake 2 levels feel pretty cramped to me). It'd be great if you can provide some screens.

Say, do you guys know any good Q1 custom maps that captures the Strogg architectural style well? 

czg's Insomnia.

but I'm sure I have played dozens of other Q1 maps that have also out-Q2'd Q2 

http://qexpo.tastyspleen.net/booth.php?id=157 

I think what the poster is referring to here are elements like the "face" textures in city2: http://i68.tinypic.com/1eaq78.jpg 

Last two levels on Travail Ep2. 

https://spawnhost.files.wordpress.com/2012/07/quake2_collage3.jpg

https://spawnhost.files.wordpress.com/2012/07/quake2_collage2.jpg

https://spawnhost.files.wordpress.com/2012/07/quake2_collage1.jpg

See the cathedral-style window in the middle of the second image, for instance. Also some pretty ornate textures, including those huge red doors and red-carpet-type floors as well as the strange tech-faces.

The palace stuff is almost churchlike in some places and more reminescent of a kind of weird tech shrine in others. One of the rooms has some sort of tech altar overlooked by a balcony that looks like a pulpit.

It's just a similarity that some people might notice, others might not. And the pseudo-religious is in both Doom and Quake 1, as well. Hell, even in Doom 3. 

Now I get it. Somehow I didn't notice these little things and how big the structures really are.

Also, what could possibly out-Q2'd Q2 itself?