I've played this map a few times on the FITH server, and I think there are some interesting things in here that I like. That being said I think there are a few significant issues based on my experience playing.
1) The layout of the map is very unclear. Even with many signs and arrows, players still get lost trying to find the objective. The map itself should be what guides players in the right direction; arrows should only be used to reassure players that they're going the right way.
2) The map varies quite extremely between either very claustrophobic or very wide and open. Generally in TF2 you want gameplay spaces to be open enough for combat to take place, but not too open where snipers become overpowered. Some areas in the map have a lot of narrow passageways, tight rooms, and low ceilings. I felt that most of the staircases and walkways were way too tight and difficult to navigate. See this spot for example:
This corridor is irritating to just walk through, let alone having to fight in it!
Other parts of the map, however, have huge spaces where snipers dominate. Look at this:
Snipers standing here have a clear view of practically the entire stage, and are so far away from the players down below that there is no clear path to reach them. They are pretty much completely safe from anything other than other snipers. These two examples are by far not the only areas with these issues.
3) This map is DARK! Seriously, put some more lights in this map! There are too many places where you can't even tell what team someone's on (really, any places like these is too many). This makes the problem with snipers even worse when you can barely even see them.