Pros:

~Detailed
~No Bugs
~Free Space (kinda a double edged sword though)
~All the texture work properly

Cons:

With the free space it's kinda easy to kill zombies but they tend to spawn behind you too so it evens out.

Camping spots, mainly the vents can be used for some serous camping and your practically unstoppable with infinite ammo but you won't always have infinite ammo so the camping spots don't work for long.

Conclusion:

In conclusion it's a well thought out map  it was well thought out and deserves a L4D2 port.