Hi, the idea of map is quite good. I like the nice looking stair-rails and the small water port in the middle.
But I think that entire map should be cca 1.5x - 2x bigger though.
To make it really playable, you could consider about these suggestions (about appearance and playability):
The map is too dark, also.. there is few of nice day skyboxes, that could be good fitting to this map I'm sure, but it is not necessary to change skybox.
And there is not enough of lighting. A lot of places are too dark and losing a possible interesting atmosphere then.
You could try to choose some better looking textures in some places. For instance, when you look at texture of stairs, it doesn't look too well, etc.
To make it better playable, I would make it bigger. Also.. on the screenshots below with comments I will show you how to improve some things.

Actual way(s) to the bases are hard to use. You can see why. About the angle of ramps,
if the map would be bigger, then lower angle of stairs would be appropriate.

Possible way how to improve way to base at the top.

Design looks good, but think about playability, if you want to keep there weapons as it is now.

Design is kept and it is much easier to get under the construction.

One of the visible texture errors.

To fix it, try work with commands for rotation of texture "vrotate" # (1-3) and with position of texture,
via F3: vtex/"offset texture up or down.."

Example of making a good looking pavement.

I suggest make this "bridge" wider. And instead of a clip at the top,
you can make slash walls and there some windows with alpha material: /alpha; to adjust permeability: /valpha (0.1-1)
And also decrease scale of lamps, because it blocks movement and smaller are better fitting.

Some places are too dark.

You can use mapmodel or correct position of texture.
Hope that my advices are a little useful at least. There is more things to do, but if you think of a playability, you can locate them and improve easy on your own. Keep up editing, it can be a good map.