Pros:

- stargate based
- challenging difficulty
- hark backs to movies, and games
- custom objects, textures
- soundtrack
- easter egg's
- innovative gameplay (climbing, flying vehicles, working stargate, gas maks, etc.)
- amusing moments
- plot

Cons:

- bots likes swimming in lava
- no vs mode yet

Conclusion:

It is "must play map" for SG-1 fans. Working stargate are piece of really great work. Gameplay is more comprehensive than ordinary l4d campagin, there is a lot of new awesome custom things, therefore it won't be boring even for and old hands in l4d.