I wouldn't consider this as a competitive map because of the 'amoury' (being where equipment and weapons spawn). You might want to make it casual before a mod notices.
On the whole, the map is very clean and well polished off. You made sure it looks good :D. The balance is good to though. You would think the person on the turret would own - but he is an easy target to pick off. Well done
this looks pretty simple, as you said, but i think it would have been better for spawning if you stretched both sides of the map a little into the tunnels, adn it would be alot bigger too.(ok maybe thats not what your goin for though)