As I'm sure don't need to be told this but your map looks amazing. From my humble first impressions I must say the visuals completely blew me away, the map looks stunning. The lighting works really well (for the most part) and the textures are well chosen with the architecture well detailed.
Now on to some of my problems with the map:
The vents are really, really inconsistent. But before I go into detail about that, well done for trying the scaling up some of the vent textures to fit playing walking height (unlike Valve on Nuke :/), it’s good to see that level of care when you first walk into the ventilation shaft. However this is also where the problems begin, whilst the textures are partially lined up in the lower T vents, they are not lined up anywhere else. I can understand that it’s quite hard to line the square panels with all the inconsistent shapes of the vents design.
Allow me to make a suggestion: scale down the size of the vent panels so that each panel is around 16/32 units high and then simply adjust the design of the vents to fit a scale of 16/32 and bingo, perfectly textured vents. Another solution would be to simply use a basic metal texture that has no panelled pattern on it, like in the ‘tunnel of love’ section of the Dark Carnival campaign in L4D2.
Now on to the design of the vents:
First you cannot shoot open some of grates on the vents. Now this wouldn’t be a problem if there was a way of instantly telling which vents you could shoot through and which vents you couldn’t, Black mesa source did a great job IIRC since the vents grates you could break open were clearly damaged. One solution would be to implement something like that into the map.
Secondly you have to crouch when you reach the top of the ladder in the vents which is a little annoying, but can easily be fixed by making the height of the vent consistent throughout.
Whilst I don’t mind the one-way system you’ve implemented into the vents, in fact I personally think it could lead to some really interesting gameplay. However the way it looks at the moment is a little weird and something about it doesn’t seem right.
Overall I feel that it’s only the really the vents that are letting the map down.
Now for one or two final points:
Personally I hate the billboards that advertise the map, within itself. Whilst they are not as hideously obvious as the billboards in Mill, they still take away from the atmosphere without any benefit to the gameplay.
The map needs a ‘.kv’ file, even if you want the map to feature the ST-6 and Phoenix factions there should be a kv to allow for some player model variation.