Pros:

Love the colour scheme
Looks more visually appealing than just the dark M9
Symmetry
Amazing animations

Cons:

Not really anything

Conclusion:

Really powerful animations with aesthetically pleasing colour choice. Love how the barrel and the slide are separate tones, and the grip being a bright orange wood makes it different. It could be both a collector's weapon, and an actual side-arm. Very nice, definitely recommend.

Pros:

Very, very good model
Darker than the default, looks more natural
Excellent gunshot sounds

Cons:

The shells on the side are in a very natural pattern. It bugs me a little, but not a lot.

Conclusion:

An awesome replacement for the autoshotty. One of my favourite mods.

Pros:

Very thorough mod, nearly every particle effect is replaced

Cons:

Effects seem oversaturated, makes them look silly
Over the top effects
Colours of certain effects don't match the default models, smoker's smoke is a bright white, instead of a more natural dark smoke.

Conclusion:

Wasn't a big fan and went back to the default. If a player is trying to make their L4D2  a little more colourful I can see the benefit, but it's not for me.

Pros:

Lovely skin
Very visceral weapon

Cons:

Magazine appears with black and pink checkered pattern

Conclusion:

Not something you can fix, or at least want to, but renders the skin unusable. I'll try the RPK skin instead and see how that goes.

Pros:

Makes the tonfa look a little more lethal

Cons:

Doesn't change the weapon too much

Conclusion:

Love this skin, gives the tonfa a little more 'oomf' in it's strikes.

Pros:

More stylish than the original
Very detailed
Flicking open the barrel looks amazing

Cons:

It's a GL, so plenty of team-killing horrors await.

Conclusion:

Amazing skin. Can't say I use the GL, but downloaded anyway. 

Pros:

Pretty good models
Good animations

Cons:

textures seem kind of flat on the models
The greenish tint is very off-putting

Conclusion:

It's an okay handgun replacement. I'm sure if I was more of a 'green' person I would appreciate it more. 

Pros:

Very well made model.
Visually matches with Arby's Glock handguns
Fluid animations, very well done!

Cons:

The gun freaks out while firing. It seems overdone.

Conclusion:

An amazing replacement for the silenced SMG. I fully promote this mod.

Pros:

Very well made models
Almost 100% accurate
Fluid animations

Cons:

Uses default pistol sounds

Conclusion:

Very good replacements, without a doubt my favourite new handgun set. Kudos.

Pros:

Beautifully adds to the look of the Deagle.
Adds a worn look, more akin to other weapons

Cons:

Nothing really.

Conclusion:

The glare and reflections on the default Deagle really bothered me, and this fixes that perfectly. 

Pros:

Nice darker shade
No new animations
Updates Shotgun with more detail if you want a better looking game.

Cons:

The sound of the shotgun firing sounds artificial.

Conclusion:

Good model, but the sound of the shotgun firing kind of spoils it. Fixable though, so it's not that big a deal.

Pros:

Beautiful animations
Very good model

Cons:

Entire gun is untextured, pink and black checkers on Mac

Conclusion:

Would really love to use this skin, it's amazing in every aspect, but I just can't while it's untextured. Hopefully this is fixed in the future.

Pros:

Good appearance
Good animations

Cons:

Gun sways a bit too much when moving, nitpicking though.

Conclusion:

Great mod, lovely replacement for the Pump-Action

Pros:

Great models
Great animations
Great sounds, gunshots really pop

Cons:

Very glossy models
Reflects light too much, especially in dark areas

Conclusion:

Couldn't play L4D2 without this mod. Love it to death, just needs a but of work.