Pros:

Excellent campaign and level design.
Very consistent across areas and levels.
Great aura, environment, and feel.
Intense crescendos and finale.
High quality custom textures and weapons.
Ammo/Supplies placed very nicely.

Cons:

None worth mentioning!

Conclusion:

I had great fun playing this map with my friends! The crescendos are very well done and the finale is quite intense. All the areas are quite spacious and well-planned, but they're not confusing or empty. I'd say this is the work of very professional and skilled people! I highly recommend it.

Pros:

Good city-scape background (from highrise).
Crescendos are intense and original.
AI Soldiers are interesting.
Custom-skinned witch is interesting.

Cons:

Some areas feel barren and empty.
Ammo is slightly scarce at beginning.

Conclusion:

I liked the campaign's custom elements, such as the custom soldiers, skinned witches, and amusing molotov generator. I enjoyed running through the levels with my friends (bile bombs are quite useful in this campaign).

Pros:

Very consistent aura and environment.
Excellent map design!
Custom music is very fitting.
Very cool custom weapons.

Cons:

None apparent.

Conclusion:

I'm extremely impressed by the look and feel of the campaign - it's clearly the work of an experienced (and perhaps, professional) level designer. I enjoyed the custom items, music, and fresh crescendos. I highly recommend this map to everyone!

Pros:

Good map design.
Ammo/supplies spaced perfectly.

Cons:

Minor bot navigation issues.
Portions of campaign feel out of place.
Too many invisible walls, too much herding.
Weapon Unlock Plugin doesn't work!

Conclusion:

Other than minor bot nav issues and the spammage of invisible walls, I had a good amount of fun. The overall design of the map is great and it seems the ammo/supplies were placed very well to promote conservation. 

Pros:

Very detailed, impressive, and original map design.
Aura/environment is consistent and transitions smoothly.
Ammo/item frequency is just right.
Flooded area is fun to traverse.
Explosive barrel room is rather amusing/frightening.

Cons:

Bot nav isn't perfect, they occasionally get stuck.
Gas run finale is rather difficult - not enough ammo/health.

Conclusion:

Although I was a bit bothered by some strange elements in map design and somewhat unreliable bots, I had lots of fun. The campaign is extremely impressive and it's the most fun I've had in a while as far as custom campaigns go. Since it's a gas run with few supplies, the finale is rather difficult. I highly recommend this map.

Pros:

Very professional campaign design.
Good continuity between maps.
Ammo and item frequency is just right.
Custom melee weapon and Tank skin is fun.
Easter egg is excellent.

Cons:

Can't really find any.

Conclusion:

I'm not surprised that this is the top-rated campaign right now. The campaign feel like it was designed and constructed as a whole - not just some linear spammage of buildings and crescendos. I enjoyed the custom textures and items. I absolutely loved going through the easter egg - it's worth bringing the gnome all the way until the end. This is bucket list quality.

Pros:

Decent map design and linear flow.
Ambient lighting done nicely.
Plenty of ammunition and supplies.
Forced car alarm near last level amusing.

Cons:

Finale was somewhat tedious.
Common infected could not reach some places.
Poisonous water unnecessary.

Conclusion:

This is a well-designed map that's worth a play. Some crescendos and areas may feel a tad unoriginal, but the linear flow and continuity of the maps are well thought out. Common infected pathfinding is lacking in one or two areas, but otherwise the entire campaign is bug/glitch free. The finale is a long hack and slash up several flights of stairs and it leaves me wondering: how the hell do all the infected get up there?

Pros:

Good conversion from Half-Life 2.
Campaign missions are relatively linear.
Items and kits placed sparingly.
Finale area is fun and spacious. 

Cons:

Light and dark contrast a bit high.
Risk of falling to your death.

Conclusion:

This was an excellent HL2 map to convert. The maps were not hard to navigate through and they still provided consistent difficulty. Despite the fact that this is a conversion, my friends and I were sad to see it end and felt it was a tad short. I recommend it as a must - especially for HL2 vets.

Pros:

Organized map design.
Cool loading screen and ending screen posters.
Good use for fridges and vending machines.
Ambulance and voice actor nicely implemented.
Wall of Death (neurotoxin) is fun to run from.

Cons:

Pathfinding was a tad confusing.
Ambulance didn't give enough time for Cola.
Airstrikes aren't too useful.
Moving to defend three different sectors is tedious.

Conclusion:

This is a good campaign and is something you'd expect out of a professional mapper. For the most part, the entire campaign is bug and glitch free. Escaping the flooding neurotoxin is pretty fun, seeing as how there's a "wall of death" feel to it. There's just a few too many things you have to do, such as being careful of the neurotoxin or defending three sectors at the finale.

Pros:

Decent implementation of Mario theme.
Very nice visuals and textures.

Cons:

Missing the appropriate music.
Last two levels have some bugs and issues.
Fall damage is too great.

Conclusion:

My friends and I very much wanted to enjoy the campaign. The first two levels were quite fun, but once we risked death at every little jump or move we made it started to get rather frustrating.

Pros:

Very interesting and fun puzzles.
Consistent theme and aura across all maps.
High replay value with friends.
Item buying system!
LAZERZ!!

Cons:

Bot pathfinding isn't perfect.

Conclusion:

I hate to reference another game, but this campaign has a very Portal-esque feel to it! In addition to a good map design, the author did very well in maintaining the campaign's theme and aura: the feeling of being constantly herded and trapped. The implementation of some of the puzzles is very original. I highly recommend this to anyone who desires a slight change of pace.

Pros:

Extremely professional map design.
Rich, vast, detailed environments.
Intense and non-repetitive gameplay.
Plot is very integrated.
"You Will Survive" mantra.

Cons:

Slightly lower FPS.
Environments are too dark.

Conclusion:

This is, by far, the best custom campaign that I've ever played. Hopefully Valve publicizes this on their blog and installs it on their servers. The feel of the maps and gameplay are akin to Bioshock or any other thriller action game - you're even hesitant to progress sometimes (either because you just want to explore/read everything or a portion of the map is just creepy). Highly recommended - better than the preloaded campaigns!

Pros:

Creative and challenging maps.
Large and vast map design.

Cons:

Too many major and difficult crescendos per map.
Map designs don't make sense sometimes, "story holes" present.
No continuity from map to map and region to region.

Conclusion:

Although it's good visual map designing, the bigger picture isn't taken into mind. There's a lot of "holes" present in the map design and transitions (no continuity and things feel out of place). I took a fly-around whenever I was dead and things just didn't add up to me. Pretty map design, but not Valve quality map design.

Pros:

Map is visually stunning, but only in some parts. 
Smooth retaining of theme and feel of the environment.
Kind of creepy in some parts.
Very straightforward nav'ing on the first two maps.
All of the maps are the right length.

Cons:

The third map needs a second new look. There's quite a few things that need improving on that:
3rd Map: floating grass and foliage, needs to be adjusted
3rd Map: Lighting is odd in some areas, such as spooky cabins
3rd Map: horrible glitch where part of team may spawn at the ending saferoom
3rd Map: need a navigation hint, possibility of getting lost, people don't like that

Conclusion:

This map has a lot of potential. I just saw a lot of issues with the third map that could be changed and fixed. And lastly: how does the survivors even get to the fourth map, which is like an island out of nowhere (and we're waiting for a boat to get us off...?). Other than that, it's visually stunning and very satisfying.

Pros:

The whole campaign is very smooth from beginning to end. No question or mystery of how map transitioned at all.
Map is visually satisfying, nothing out of place.

Cons:

I'll just place this sentence in here because this field is required.

Conclusion:

The finale was very difficult, especially with two tanks and so many ways in which the infected could flood in. Other than this, this is Valve quality mapping. Here's to hoping this gets loaded into their servers as a Valve pick! Cleanest map I've ever played.