OK I checked the map out, couldn't get anyone interested enough to play it with me, so it was a solo run and I tried to imagine gameplay taking place.
First off I noticed the map had the same colour scheme (basically the same texture) everywhere, which made it, initially hard to navigate at first. I found my way around after a few runs, but there was nothing in different areas of the map that stood out to help navigation. Because of the lack of variation in colour I wasn't able to tell which base I was in =)
If you make the bases really distuiguishable, it's a lot easier to play a map. 
The map itself feels really flat (seems to be a really common occurence). I know you have ramps that go up and down, but it doesn't really do anything for gameplay in the way you had it, as it didn't really offer and advantage or disadvantage.
I was also able to see from one end of the map to the other almost which as a sniper gave me a clear view to their capture point, not a very good design choice. In general there wasn't much though gone into the capture point placment and what tactics are needed to capture them. In my opinion I don't think you should be able to have capture points see each other. Too easy to camp etc.
I see you placed some of these concrete blocks as cover, good attempt, but you may also want to try and place some variation in the cover, smaller, shorter, wider etc. This can vary the combat and make the game a bit more interesting for both teams.
You also want to keep in mind that this is a class based game, therefore try and design small areas to keep people playing those classes happy. Place platforms or create areas that give someone like the sniper a good advantage point to sniper from. You want to also keep an eye out for spots that may make good gathering/healing points for engineer supply units, always handy in the heat of an attack.
I wouldn't quite go to town like you have on model placement, while it may seem fun and enjoyable to add heaps of cool models it doesn't always make the map better =) Always put a bit of thought into model placement and offer up a story to every model you place, why are these tyres here? "oh, that is because jimbo was changing the tyres on the truck" etc. This will help create a more believable scene 
When placing models, either place it flush against a wall with minimal gap, or far away from the way where the player can run past it and the wall. I found a few models that were placed I though I could run between from a distance, and if you're being chased by someone and you get caught between a model and a wall it can be very very fustrating.
There were a bunch of floating models throughout the map, most noticable were the boom gates, the truck outside the boom gates and some crates.
The god rays that were placed near the first capture point for each team didn't really work, at first I thought there was something wrong with my screen 
but then I realised what they were.
Try and make sure you test your map buy running around it, and clipping things, I got stuck on some models along the walls. All it needs is a small box to engulf the model and a few small bevels on either side. Also never use a team based clip brush to block the enemy it is a very very lame thing to do (sorry for being harsh but I can't stress this point enough) use team doors and create the spawn areas in such a way that it gives the home team a major advantage over spawn campers.
Over-all performance seems to suffer a bit in comparison to TF2 maps I run the game with maximum settings, 1280x1024 with 4xFSAA and 8xAF and I get flawless performance, but I got 40-50fps in this map. You may want to keep performance in mind when building a MP map you want other people to play. Low FPS = no play.
