Well, seems time to comment. Even this seems to be your first map on quadropolis, you can also sense some (small) help of others within the map. Next to that, as there are a lot of people only giving a comment, yet no feedback; you can expect the opposite from this one.
As others already stated (and so did I) the screenshot contains a very poor quality. As you've stated, the map definitely isn't finished yet, as there are still a lot of things to improve. Quadropolis isn't just meant to dump your maps, models, textures, skyboxes, scripts, etc on to keep them preserve for around 5 years while people observe your map once in a while, but also meant to post stuff on and receiving some feedback; which you can use to improve it (don't rush to the next map immediately).
Some more info could have been added. but ah well, it does the job so far...
The theme seems to be oldskool industrial (similar to metl3 and turbine). Yet you only took 1 specific theme instead of combining 2 (as egyptic and industrial for metl3, while being industrial and quicksand for turbine). This makes the map pretty weak on that aspect, as it's all pretty much the same style; there's no contrast. This will be more clear in the next couple of points.
The texturing could be improved by specifying them in a configuration-file for the map. This gives the opportunity that the light-textures are really shining instead of being pretty dark for a light-source. A good example to see the difference is to observe the light-textures within mbt10 and
your own. If you don't know how to do this, there still is some "trick" to get some similar result which I'll explain later.
As the textures show, the map should be dirty and dusty. Yet I don't see any real dust, neither dirt around (except the sandpit). What about textureblending some paths on several hallways and platforms?
The geometry isn't bad, yet it's missing something. The skybox shows off a lot of height difference, yet there is almost nothing of that inside your map. What about replacing some of the buildings for some more rock walls? Take for example the screenshot under this line, which could easily be replaced for a nice looking rock. Keep in mind there are way more places that could benefit from that.
The lighting isn't bad, but could also use some tweaks. As I stated at the texturing, the light-textures aren't convincing to emit light. This could be fixed by adding a light-entity with a small radius, yet being very intense (like the colour-parameters 255 255 255); very close to the light-source. A good example for that is the map metl3, which shows off this lighting-technique very well.
The map isn't having a very nice atmosphere, because of several points. The first one is, there are several areas which contain a clear light-entity, while there is no light-source in the scene (and also the opposite is appearing within the map) and the second one is, the sunlight; which is around the same colour as the overall textures are (creates a somewhat camouflaging effect). Next to that, the skybox creates provides no contrast either, as it's also brown in overall. So in other words, provide some contrast in the map. It's not bad to have a skybox which is a different colour as the overall textures, as long as the atmosphere fits the skybox also. Another solution is to provide some different coloured light-entities instead of having a somewhat orange colour on them.
The screenshot under this line is showing of a good example of a light-entity which isn't containing any light-source (so realism gets killed).
There are a lot of details, yet they aren't really popping out. That's not a bad thing, if they were pretty original and also not overused. For example, a lot of scrolling textures have been used. Not bad to do so, but having 8 different scrolling textures on your screen gets a little dull.
The details itself aren't also sticking to 1 theme. For example, the sand-current idea which is just based on a sand-texture that's being scrolled over some geometry quiet fast isn't fitting the rest of the map, as there is no sense why the sand-current actually exist. In the map turbine this idea does get explained (as the hills seems to provide it), which makes it logical and makes it fit into the map. Another example for that is the pool of water which has been added; where is the sense of that?
So don't just add details because they may look nice; add them with some sense. Don't worry, you'll probably get that sense when you've done some more mapping; it's a common mistake which (almost) all newcomers do (even I probably did; as side information).
The clipping is pretty bad. There are a lot of places which are clipped, but somehow a lot of things aren't. Also be sure to add a ceiling of clip above the map, as people are able to trickjump their way up right now (by doing a rocketjump while holding the quad for example or even doing a double grenadejump).
Try to fix all the mistakes, as it's really a big number. A very good example of some mistake (and the lack of a clipped ceiling) can be seen in the next screenshot.
The flow of the map isn't bad, but not that great also. Some clipping makes you bump your head against the ceiling and some areas could use some more difference in height or just being less open (the area which the YA spawns nearby for example; it doesn't fit the rest of the map at all).
Having some holes in the sandpit isn't a bad idea, but try to use a bigger gridsize for those holes, as they feel very bumpy right now. Some height-difference between geometry should kept preserved, but a real choppy ride should be avoided. The best gridsize to do so on this map would be the same as you've used for the bumps on the ramp made out of sand.
There are several playerstarts being positioned half-inside or very close to geometry. This calls up the risk of having players spawn into the geometry, which makes them fall off the map and suicide automaticly - not a good thing. So keep the playerstarts a bit away from walls (and floors; just the default space between the entity and the floor when calling up a new entity should do).
There are several rooms which seems to ask for another path (even a teleport or teledest would do), as for example the room right above a teleport.
The teledests could also use the option of having velocity preserved while using the teleport. Just put a 1 in the 3th slot of the parameters of the teldest.
Some screenshot about that ceiling of clip is just right under this statement.
The gameplay isn't bad, but could also be improved. As it's a pretty big map, having 2 green armours wouldn't be that bad for the gameplay. It's very unlikely to get a proper duel on a map of such size.
There can also be added way more shells, bullets, grenades and even cartridges (not too much of cartridges though), as there are 7 riflerounds appearing on the map (and 6 rockets) while all others only have 4 spawns to appear on. So I would advice to add like 4 more shells, 1 more bullets, 2 more grenades and replace 2 rockets and 2 riflerounds at least. There still are several areas which aren't containing any ammo, while other have like 3 different types of ammunition.
Having 2 quiet dominating type of ammo isn't a great move to do let players deal with, as it provides no variety during play.
This map seems to be quiet good for (regen)capture, as it contains several paths, yet having cover (which is a good thing). Maybe you should add some bases around the map (I think like 4 or 5 would do).
Here an example of some pickups which aren't really tactical placed, while also having an area which isn't really having any purpose (like a path or spawn area).
Even there are several people around here which just mindlessly rate the map 10/10, I noticed after some proper viewing that the map isn't that great as people believe so. It still has a lot of work to improve, but I'm sure it could be worth to do so (as the layout seems pretty solid). Nice work, but keep it up and make something beautiful of it.
All screenshots within this comment have been resized with Microsoft Paint =P.