2 more things. Particularly regarding:
http://uppix.net/d/8/6/be02e7a07ed7949c63a84948d3139.jpg
There is such a thing as too much detail.
I'm not saying this because i'm competition, but there's a reason why Valve maps don't have this level of detail content. Players need to be concentrating on enemy players, secondly they also need to be able to run the map in the first place.
This much detail distracts players from the gameplay and even camouflages players. Players arn't spending most of their time looking at map detail. Even though this is a detail contest, if you check out maps like goldrush you'll see that most of the map detail is faded out beyond ~1024 Hammer Units; including the tracks, a gameplay related model. Just because there is a wall does not mean you have to slap windows all across its face. My most common advice to ammatuer mappers is "
more props does not = a better detailed map".
You need to balance player legibility, performance and theme (more props does not necasserily allow you to narrate your map better, infact it usually confuses the theme). There's simply too much visual input for players in this current environment.
This isn't Crysis and shouldn't be treated as such. Please,
please bare this fact in mind. Overkill may superficially look great, but it has negative connotations for a reason.
Here's a tip: Detail areas where players naturally look. Doorways, corners,
large bland walls, the horizon silhouette and objective points are the obvious ones. Having tens of high poly models 1024+ units high in an area barely 512 units wide is not good detail sense. Players may look up and acklowledge that detail once or twice when passing through between spawn waves, but during combat it is ignored and detrimental to performance. Design is problem solving and compromise. You have not compromised. One or two empty walls or a wall with just an overlay is not a bad thing and does not mean the designer was lazy or incompetent.