Pros:

-The L4D1 Common Infected in L4D2
-No Glitches
-Gives back a truer environment, like the nurses in Mercy Hospital
-Brings back the Military and Police Infected

Cons:

Cons you say?? Why no I don't have any!!

Conclusion:

All in all, this is an amazing mod. I get the atmosphere that I have been longing for since the first time I played L4D2. I have missed the Surgeons and Nurses, as well as the Police and Military Infected.
I would also like to congratulate Tails1 for his incredible Modding skills, no one else has ever figured these glitches out!!!  You sir, are brilliant!!!