Pros:

*Great environment, each map has a unique feel to it
*Great flow from map to map, fairly well paced
*Well optimized, except for a few laggy areas (particularly where there's water)
*Nicely tuned for versus play
*Great attention to detail for a beta
*Easily the best desert-themed campaign I've ever played

Cons:

The color correction is a bit too extreme.  I'm guessing you're going for a sepia tone sort of thing but you need to turn it down a bit as it is a bit glaring (the sand is so bright its almost white), it makes me feel like I'm walking on Venus.

A few maps are a little bit long for versus, and I think map two (I think) might have some nav flow issues... It scores points inconsistently (giving more points to the team that made it less far).  You may want to double check to make sure that the manhole cover that you open up from later in the level blocks the nav so that it doesn't make that ladder part of the escape route path.  There might be something else at play there, not really sure.

You might want to consider adding some sections of some of the maps where tanks aren't allowed, as there are some really really tight areas where its just incredibly difficult to fight a tank, especially in versus.  (Contrary to what some other reviewers have said, I encountered nearly a tank every map.)

A couple ladders could be added on the sides of the sandy hills, as its difficult to find spawns in some of those sections.  I know ladders going up displacements is kind of a pain but it's doable.

The radio audio on the finale is a bit overly scratchy sounding, and I had to turn down my volume a bit.  I'd turn down the noise effect a bit on it.  Also, the finale, as well as a few of the other maps, could use more melee weapon spawns.

While most of your map was pretty well detailed, a lot of the walls along the military base were kind of blank looking and textured all with the same grey-ish color.  Otherwise the level of detail you have is great.

Conclusion:

Great campaign!  This has become a new favorite for versus among my group of friends.  With a couple bug fixes and toning down the color correction, this map will be perfect!

Pros:

*Each map presents a unique and distinguishable type of environment in terms of layout and scenery (though mostly set in an urban environment, which is also very well done aesthetically on the whole in terms of choice of texturing and what not)

*All the maps are very challenging with some quite impressive hordes (at least in versus), making it a very fun and rigorous campaign to play!

*Optimized very well as far as I can tell, runs perfectly on my computer, even with all the water, very impressive.

*Very unique event with the fire triggering the boat to cross the bridge.  Very creative.

*Any bugs that I noticed in previous versions seem to have been cleared up with version 3, it works perfect, and I mean perfect from beginning to end, which is rare for a custom campaign.

*A unique finale that separates itself from parish as a running event, particularly with the football player melee weapons and tanks.  Navs and scoring are in order too, which is always nice to see.

*Balanced very well in terms of versus spawns, ladders, etc.  Never once found myself in a position where I couldn't find a spawn.

Cons:

*The custom voice audio for the train guy and the radio incom was very scratchy, I realise this was on purpose, but it seems a little overdone and just makes it sound like bad recording.  But this honestly is such a small issue that I wouldn't worry too much about it.  It's the only thing I could think of.

Conclusion:

Overall, this is the funnest versus campaign I've ever played yet.  I simply love the amount of detail and work that has gone into this to make it just as good as a campaign, if not better than the original Valve maps.  It beats cold stream to the ground in my opinion (though that's not really fair, I realize, since cold stream is still in beta, but I digress).  The one con mentioned is so little an issue it's barely worth mentioning.  I'm glad you fixed up the bug on map 2 with bots not picking up weapons and ammo, and I haven't had any trouble with the finale since the new version.  I'm not one to give campaigns 100/100 (this is the first campaign I've rated 100), but honestly, this is as solid and perfect a map as you can get.  It even has scavenge and survival!  I've got a lot of people I know to download it, so we're going to be playing it a lot!  Brilliant job!  I sincerely hope Valve picks up on this.

Pros:

Very Unique Design and Layout.
Nice Visual Cue Texts
Love the Name, though I dunno why you have it lower case.
Nice detailed job on every map.
Good Finale with a working points system.

Cons:

Certain areas look a bit blocky, but its a beta so thats to be expected.
Map 2 is very long and confusing.  I'd either make the beginning simpler to go through or include a lot more arrows around the map to make it perfectly clear to the survivors where they need to go, as I spent a long time wandering around in circles.  
The other two maps could use a bit more directional help as well.
I'd recommend splitting map two in into two maps, as it is extremely long in its current condition.
The part of map two at the beginning where you jump into the little shaft, the bots do not follow you in at all.  I'd recommend making the opening larger and including a small plank to walk across to get in.

Conclusion:

Needs a lot of work, but shows great potential.   I definitely look forward to future versions.

Pros:

Same Pros as I gave for the normal version
The new map (or old map I should say) that's been added is a nice change of pace for the campaign.
Some of the changes I've seen here I'd like to see implemented in the main version, particularly with the events on map 4, which I've also mentioned in my other review.

Cons:

Map 1 was a strong start for the campaign in the original version and hate to see it go, but adding this would be worth it if you could change a few things.
First off the new map 4 is a maze at the beginning.  It is very difficult to find your way even if you have done it five times before.  Arrows on the screens are a nice touch, and I'd recommend adding more of them in versus if not in campaign.  I'm all for non-linearity in campaign modes but in versus the path that you need to take should be well apparent to both the survivors and infected in order for it to be fun.  (Right now either the survivors cant find their way and get killed, or they make it very easily since the specials can't figure out where to spawn).
The forklift event could use some work, I'd recommend adding a progress bar or going into third person when you are triggering it.  It is difficult to tell whether it is moving at all.  Perhaps rather than trying to hold it down like some of the other events in this campaign, you just trigger a generator to power it up that will, once charged after the horde, make the forklift move.  Like with the normal version, scavenge would be an interesting addition.

Conclusion:

Not quite as good as the normal version, but with a couple bug fixes it would be a very nice alternative.

Pros:

Shows potential of being a nice campaign
Nice choices of setting
Good optimization and brushwork

Cons:

Terrible Infected spawns in versus on some maps and overpowered on other maps.
Area Effect triggered events are a real pain and annoyance.  Please, try and make some these more easily triggered by the survivors by use of a button push or something.  Using an area affect event every now and then is fine, but you used it rather excessively.
The city is probably one of the most ridiculous maps I've ever played.  It's relatively fine until you get to the alarm cars.  There are simply so many of them (most of which aren't even marked) that it is impossible not to set one off.  And the horde does not end.  I tested this myself.  I set one car off and the horde went for over twenty minutes before I quit.  One or two alarm cars are fine but having as many as you had is ridiculous, and please include more ammo spawns if we are meant to fight such a ridiculous horde.
The finale is rather dull.  I'd recommend changing the layout of the base to make it less open, perhaps add something to it to make more exciting, such as maybe extending the interior part of the base to more than just the entrance.

Conclusion:

With a bit more versus testing and some balancing, this could be a nice versus campaign, but in its current condition it is simply not fun at all in versus.

Pros:

Brilliant looking, wonderful design and atmosphere, lighting.

Cons:

Poorly optimized, I'm running a 3.2 GHz quad core processor  with a nvidia GTX 320 cardand i still get 20 fps in most places.
Ladders (not just infected ladders) are poorly constructed, objects jut in the way of the ladder making them hard to get up, and some are placed too far away from any ledge to jump on to.
Scavenge mode doesn't work right, the timer starts right off the bat with no set up time.
Scavenge mode crashes after one round, this may be related to the poor optimization but I'm not sure.

Conclusion:

A wonderful looking map that is too buggy in its current condition to really be playable, not in scavenge anyways.  I hope that the ladders get fixed (again apparently) and scavenge mode working properly.  I look forward to seeing this completed, so please make sure you have it tested and fixed before your next release, as all the problems with the original version are still there.