Pros:

o    Beautiful, detailed environments
o    Nice environmental variety, keeps campaign interesting throughout
o    Excellent use of environment to create fresh challenges on every chapter
o   Challenging but not overbearing

Cons:

o    Most chapters are too brightly lit, not enough moody lighting to create a sense that this is a zombie apocalypse
o    A few bugs here and there, nothing game-breaking
o    Maps, especially the bridge area, have a few areas where getting stuck is a problem
o   The gnome disappeared through the floor a few times trying to carry it across the bridge
o    What's the secret to the gnome?!?!

Conclusion:

It's a sad fact that many custom maps and campaigns are mediocre or worse, that's why it's important to leave positive feedback for those campaigns that not only surpass the mediocre but demonstrate a level of professional aptitude that it could be its own DLC. 

Day Break is one of those maps. 

Day Break is a Valve-quality map right up there with Dark Carnival or Cold Stream. The attention to environmental detail, and the variety of environments makes this a fun map to play through. The map-maker took advantage of many different tricks and techniques to create a challenging but fun campaign that rarely gets stale. Save for some "quality control" issues in a few places, this is a great map that really should be brought into the Left 4 Dead 2 fold, much like Cold Stream.

Other than that, the mapmaker could have been a little more aggressive with moody lighting. With the exception of the finale, maps are brightly lit, which is fine but could have been improved with something more ambient befitting a zombie apocalypse (not necessarily dark, but something more akin to The Parish).

Regardless of these quibbles, this is a fantastic campaign that everyone should play.

Pros:

-Nice Environments
-Some nice touches throughout every level
-Clever use of original dialogue to fit the story of this campaign

Cons:

-Ridiculously long levels with obnoxious and poorly designed zombie gauntlets; The Dam area is particularly loathsome as it requires repeated back-and-forth across one area to complete successfully
-This is meant for competitive play? The level layout and endless zombie gauntlets mean there's zero chance of a team of survivors getting very far.
-Horrible, tiresome, needlessly convoluted, horrible, unbalanced, poorly designed, did I mention horrible? finale.

Conclusion:

The one common mistake that I see 90 percent of map makers do is believe that nonstop zombie hordes and panic events and gauntlets are a good thing. Wrong. The other common mistake is that a longer map is a better map. Wrong again. This campaign commits both these ridiculously obvious but common mistakes to the point of GROSS INCOMPETENCE.

The campaign itself is nicely designed, nice details and touches throughout. But every chapter is a long, tiresome and often confusing slog. It's as if the map maker kept adding more and more to the map and stopped to to say "perhaps I should stop here and improve its focus and readability. NAH... LOL!" I'm pretty sure that's how it went down.

Moreover, considering the length of each chapter - and the sheer amount of panic events and gauntlets - it boggles the mind that the mapmaker decided this was for competitive play. An experienced infected team will absolutely slaughter the survivors with a campaign this ridiculous; a boomer or two and a few well timed attacks and the first zombie panic even will usually do the job (about a third of the way each chapter). Sorry but this would be a horrible versus campaign.

But the cherry on top of this boomer bile pie is the absolutely mindbogglingly bad finale. You're expected to fight two tanks, run into several narrow corridors to grab a keycard in a tiny enclosed space, all the while fighting another endless horde of zombies, which leads you to swipe the card you acquire on the opposite side of the area you had to get the card only to be faced with more enclosed areas which would make any spitter infected overjoyed. What a horrible ending. It's apparent that this mapmaker has no semblance or notion of what game balance is, and indeed, he or she must play with some mediocre infected players if they believe this map would not lead to near-instant incaps. I'm all for proper balance between hardy survivors and frail infected but this campaign demonstrates the designer's failure to understand that balance. I hope they never make another mod again and - in fact - they should retire from Left 4 Dead 2 immediately.