Hey Rock,
First off thank you for submitting. Getting right to it I don't think a map like this would work very well in its current state. Although the old nobuild was arguable one of my favorite maps ever there are some things that hold this back. I think it is far too easy for humans to win, one big reasons the map was good on classic was the fact that the server usually had around 20 people on at a time also the map was 10 minutes long.(although I don't think you should change the time to 10 minutes) The current time seems far to short in my opinion especially because the server doesn't have as many people on anymore it makes it hard for the first infected to get it started. Something else that adds to this is no sprint. Personally I feel like no sprint maps are going out of style more and more people prefer maps with sprint which is understandable. It is more fast paced and really changes the game when it comes to a map like this one. With no sprint enabled I could see everyone easily outrunning 1 zombie around the top of the map especially the lip around it.
To summarize, I think the round time is too short, I think some sort of speed effect/sprint should be added, and the top of the map seems too human sided. Until there are 3~ zombies around there doesn't seem to be anything really that would offer much of a challenge. (I don't think however, all these points should be changed at once only 1-2 because if you changed all of them it would likely make it more zombie sided) For example something like this in my opinion would be worthy of testing:
Same map with sprint and slightly longer round, or no sprint or speed effects but the connecting beams on top are removed/changed somewhat longer, or something you think of it is your map after all.
Overall I am going with a 0 for now because I would like for a map like this to be tested I just don't believe right now it is ready for it.
Thanks