Pros:

(Map mode)
-Definitely a re-enactment of a natural disaster
-A lot of effort visibly put into map design
-Epic song and finale moments
-Creative re-use of existing doodads (such as the Howitzers into flamethrowers)
-Supply overload did not make finale too easy
-Building collapse!
-Lighting is natural i.e. dark when it's needed, bright when it's needed
-L4D1 Survivors
-Epic ending, those cliffhanger type

(Survival mode)
-Lots of easter eggs from the map mode
-Timely addition of the OST at each medal, along with natural disaster
-No need to decide where to camp; the firing line is right in front of you
-Ample supplies to last to the Gold Medal (at least)
-One of the maps that offers a full party of M60s and M79s
-L4D1 survivors

Cons:

(Map mode)
-What's a witch doing there
-Tank spawn is not always guaranteed (during map walthrough)
-Lack of directions inside the building
-Starting medkits only enough for three?
-No explanation for the appearance of L4D1 survivors (not important, but since the story of this map is already there... why not =D)
-Map's kinda short

(Survival mode)
-Gas cans do not respawn on round restart
-L4D1 survivors do not despawn upon round end (making a restart try much easier if you have progressed a lot)
-Gold medal is easy even on Single Player
-Midnight Rider bus is counter productive, and difficult to access for the survivors

(Both modes)
-Bill is spawned on a weird spot, unable to pick his Hunting Rifle and do just about anything but keep running on the spot
-L4D1 survivors takes stuff from the supplies. No big deal, there's a lot to begin with anyway, but yeah.
-Howitzer placements caused some problems with movement, especially when bile-blinded. Tank spawned between the left cannon and the table, and was unable to do anything except to throw stones
-L4D1 survivors were invincible, we left two Chargers pounding on Francis and Louis, so we had no Chargers to deal with.

Conclusion:

There is no doubt why this was "Natural Disasters contest winner": it's simply one of the best, if not the greatest, map ever made by the community, hands down. An exceptional example of working with whatever is available in the game.

This gets a final score of 9.9. The cons were simply nothing when compared to the pros, except maybe movement being blocked by those Howitzers.

Pros:

-Original idea for a survival arena
-[SPOILER]Hilarious teleportation for (human) players stuck in the starting area when the survival starts
-Merged all uncommon infected in one map, spawning them regularly
-Floor is clutterless unlike regular maps where the items are simply strewn all over the ground
-Three modes of handicap
-Barriers are actually useful
-Nice slow-mo with the fire barrels
-Aesthetically well designed

Cons:

-Walls were still breakable in Easy mode
-Lack of anything for the Tank to smash
-The doors don't recognize bots and won't open for them. Same goes for auto-teleporter when they are trapped in the starting area
-[SINGLE PLAYER SURVIVAL] Maybe it's just me, the bots are always picking the SPAS-12. Maybe allow for more gap between each weapon on the rack? They would sometimes, on luck, pick the autoshottie though.
-[NORMAL AND HARD MODE] Jockey or Charger knocks players off the sides = death. Maybe make it cling on the edge for Jockey?
-Not too sure, but my team only found one trap on Easy mode
-Machine gun posts were kinda useless, we had zombies in every direction
-Info desktop weirdness; why would there be a witch in both Survival and Scavenge?
-Lack of pills/adrenaline, or rather, they were available, but not enough for a whole team

Conclusion:

Despite having a larger list of cons, they were mostly trivial issues. My team held out pretty long on two occasions, one of them at the high spot where the second machine gun was, for approximately 32mins, the other at another room, where we held till we got bored and quit the map lol. One particular irritating point was the sides of the map. We really hoped you could make it high enough so that a Jockey wouldn't outright kill a player by riding him into the water. A Charger would be a different story, though.

Overall, good map. We are still playing it!