First: Nice layout ! You can really make your way very fluently nearly everywhere.
And big maps are good
I also like the trickjumps that i discovered (i bet i missed some).
So i just have to bug you because of the visuals and the lighting.
I'm really not a friend of walls or ceilings that are only 16 units thick. It always looks like paper-thin walls, and i never get the feeling that i could run through this environment in real life. Ok it's a game, but it's much more pleasing for the eye if you'd use thicker architecture here and there since somehow this whole map shouldn't look like it'll brake together the next moment. You'll never see concrete-walls that are so thin.
Your map is big, so GO BIG !
Some suggestions
Make the ceiling bigger there. Maybe even make the hole and the joints bigger.
Also a additional red stripe would break up the plain grey up there.
I see that you're going for a minimalistic architecture, but it shouldn't get so boxy imo.
Maybe add a pillar to fight around. It's a simple piece of architecture but i've had a lot of good fights around simple pillars, so i believe that it could add to the gameplay
A little bug where you can see through the wall of the upper corridor. It's the same here: make a bigger ceiling or even make the vent ca. 3or 4 times larger and place it in the middle of the room. Add some supporting architecture around it and you've got a great ceiling.
In this area you can really go crazy ! Place something HUGE there. This area should define the look and setting of the map! If you have a great idea about this place you can even adapt the idea on the rest of the map and this'll add a LOT to the atmosphere. It really needs something impressive. I just made a fast sketch (yeah, i suck at drawing) to give a vague impression of what this could look like.
GO BIG THERE !
And well, the lighting all over the map is very flat. Try to use different textures for lights on the wall and lights on the ceiling, and vary the colour a little bit, so that not everything is the same plain grey.
And please do yourself a favor and make another sky

This always adds a lot to the overall feel.