Pros:

Creative ideas with heaps and heaps and heaps of engaging details (e.g. the old brit cars, bathroom mat, phone box adverts and Dead Snow - 10/10!!
Plenty of zombies
Weretanks! And Trevor!
New melee weapons.
The TV broadcast
Accurate moorland and building modeling
Evocative lighting and atmospherics
Brilliant campaign ending finale
Very good bot behavior (mostly)
Flawless download and installation - plug and play
Potentially right up there with Blood Tracks, I Hate Mountains and Dead Vacation as top-shelf aftermarket campaigns that match or beat Valve's originals.
Excellent music.
Loved the new voice talents!
Broken bottle melee weapon - classic UK.

Cons:

Game crashed every time at the end of each map and once partway thru Map 2.
Bot refused to enter the elevator but went back down the acid house building.
(Other camps run fine on my gear, these problems have to be campaign specific.)
Uses the L4D2 characters instead of the Real McCoy's of L4D - that's just me tho! :P

Conclusion:

A highly attractive campaign that (perhaps) needs some tweaking to run right.  
Map 4 (the underground mine sequence) felt unfinished and lacked creativity compared to the other maps and the sections bookending it.
8.5 rating for the above factors.
All in all a darn fine effort that with some technical polish would be an easy contender for one of the Top 10 aftermarket campaigns.  Bravo!    

Pros:

Decent length with plenty of detail.
Stiff combat.
Easy navigation once you get your bearings.
It's for the ORIGINAL L4D!!!
Captures the spirit of the original game.
Easy to download and extract - plug n' play maximo.
Exciting Finale.
Bots are excellent on Single Player.

Cons:

None that I can think of.

Conclusion:

An enjoyable and edge-of-the-seat adrenaline ride.  You would be a fool not to include this campaign in your library.

Pros:

I downloaded this campaign after it was featured on the L4D blog - this is my usual "maven" source.  I was not disappointed.
1. Fast download and auto installation - no worries.
2. Stunning map work - very creative and packed with aesthetic and game-play details.  Really professional job.
3. OE quality game play - totally immersing from the get-go.
4. I liked the heavy dependence on Tier 1 weaponry early in the stanza - really keeps you on your toes.
5. Superb use of Survivor dialogue - they are very talkative indeed.  This is well above the level in the OE games and adds huge value to game play enjoyment.
6. Unlike some other commentators, I experienced no technical glitches of any kind.
7. Great ending scenario - very intense and the final cut-scene in the escaping train car is poignant and very creative.
8. Well done on introducing new melee weapons - excellent value added.
9. Great atmospherics in the maps, props, lighting and environmental attributes - one is taken into a post-apocalyptic world.  Full immersion - great stuff!

Cons:

I couldn't think of anything.  Personally I liked the plethora of gas bottles and gas cans that others have mentioned as a detraction.

Conclusion:

A short campaign [it's about as long as Crash Course] but so packed with action and beautifully environmental detail that this is not a problem - in fact, I wanted more!!

Any L4D gamer who respects the Original Experience game would be a fool not to add this zinger to their collection.

Hats off to the this campaign's gifted creator.  Well done Sir!  I hope you continue with your endeavors and look forward to your next effort. Bravo! 

Pros:

1. Fast-paced campaign - it never "chugs".
2. Bright lighting - easy to see and interpret the action.
3. Clever and creative visual touches - the bowling alley and movie theater are examples of this.
4. The Finale is a thrilling experience.

Cons:

1. Somewhat linear navigation and action sequences - very predictable after even a couple of play-throughs.
2. Generally arcadish gameplay - lacks atmosphere and a good team [even with bots] will "blitz" through the maps with little difficulty.
3. Bots fail to get on the train.
4. Game usually crashes at some point.
5. Lacks challenge after a couple of completions.

Conclusion:

I tried to like this campaign but its insistence that I play arcade style, associated lack of challenge and regular game crashes mean that I believe the underlying concept and visual artwork were beyond criticism but that this campaign's execution let it down.

However this entirely personal opinion should not put off other gamers who enjoy straight out, high velocity action [and presumably have more reliable computer gear] from downloading this campaign and giving it a whirl.

Pros:

1. An edge-of-seat action campaign.
2. A visual delight.
3. Uses L4D original survivors.
4. Professional quality thinking and execution.

Cons:

Simply cannot think of anything notable.

Conclusion:

This campaign is absolutely first-rate.  Its designers evidently have world class talent and have used it to produce a professional-plus quality campaign that delivers in all ways and at all levels.  A visual and action feast that I cannot praise too highly: this campaign is better than any of the source game's original stanzas.  Bravo lads!

Any L4D fan would be a fool not to include this stunning winner  in their collection.