Pros:

-Very large map.
-Plenty of different spots to hold out in.
-The caches of ammo prevent camping for long periods of time.
-Fun things to do for starting the crescendo.
-Spread out cans for scavenger making it more difficult (difficult is good :P)
-Having to actually find your weapons instead of them given to you.
-The Cake isn't a lie

Cons:

-Ummmm..... can't think of any.

Conclusion:

A fantastic survival/ scavenger mode map. I'd love to try it in vs survival if it ever comes back around in the mutations.

Pros:

-Good level design.
-Crazy plane one chapter 4.
-Survivors talk at the start unlike in most campaigns.
-Tough crescendos.
-Long.
-Valve mentioned this. (Gratz BTW)

Cons:

- Really really smokey in one of the buildings.
- Very confusing. (Add some more arrows.)
- Finale is really easy.
- Weird floor texture in the train.
- Odd use of the storm. (It's good it's just kinda odd how the sky goes from sunny day to OMG it's the storm!)
- Custom music not needed and is really loud can't hear the specials coming.

Conclusion:

This was a very fun campaign it was longer than most campaigns out there but not to long to get annoying. Very well done and congrats on having valve mention this.

Pros:

A great conversion of a great campaign from the original.

Cons:

Finale really easy too much bile makes it really easy to run down.
Too many ammo piles.
The last few maps the sky is REALLY REALLY bright for some reason.
I saw the void on the skybox a bit.

Conclusion:

This was a great map in the original and it's even better in l4d2 with the new infected and weapons.

Pros:

Fun to play.
It's Mario
Fun ? blocks.
Piranha plants (scared the hell out of me at first)

Cons:

The outro for the campaign is kinda... weird a totally blank white space and it has so weird effects with the survivors. (I was climbing on thin air and coach was hanging onto nothing)
Bots hate most of the maps. (understandable though)
Bots don't pick up a lot of the items.
A few bad spots for witches to spawn.
Needs more custom music.
Finale is kinda confusing.

Conclusion:

This was a very fun campaign it was unique and different. The platforming parts were really tough with bots since they like to kill themselves. I would like to the flag music when you climb the flag. Overall this was a very fun campaign.

Pros:

Nice Voice Acting.
Fairly long levels.
Tough.

Cons:

Too many small crowded areas.
Not enough items.
Little to no ammo in the level.
Tanks spawn in bad areas I.E. ladders in the second map.
In some spots not enough information that your starting a crescendo I.E. the howitzer in the second map. 
Confusing at some points.

Conclusion:

I played this in single player it was pretty fun but there were a lot of problems I saw like that there were like no items anywhere in the maps I ran out of ammo after fighting the tank right at the start and had no desire to turn back since I got pretty far and hoped for a ammo pile but didn't see any until the the safe house.
After I got to the second map I hoped somewhere along the line I'd find a tier two weapon around the middle of the map since it's only a 3 chapter campaign but I only found a pump shotty and SMG and had a tank attack me in the really tight office area which almost seemed unfair to me but I didn't care about that so much.
Lastly some of the crescendo events aren't clear that they start the horde I shot the howitzer on the second map and never heard any horde music until I started climbing down and got pounded.

Don't get me wrong it's a great campaign but I feel there are some minor problems with it hopefully you'll update this and fix some of the problems.

Keep it up.

Pros:

Arctic Tank Skin.
Great fire.
Voice Acting. (Yes I  was able to understand all of it)
Good Story.
Love the hard rain inspired layout.

Cons:

Dumb bots (nothing new there)
Bots don't pick up first aid
Finale is way to easy just hold up near heli and the infected can't climb directly up to you or come from behind.
Not as much of a towering inferno as I thought.

Conclusion:

Playing this map is very fun many creative ideas such as that crescendo after leaving the safehouse that lasts most of the level that part was way more difficult than the finale itself. That part where you must cross the scaffolding was annoying as hell since the bots thought hey lets commit suicide and I didn't happen to see any hero closets which can get pretty annoying if you happen to get flung off the side of a building.

Other than those problems very good map.

"Did you guys set the building on fire?" lol