This map pack comes with
Two Call of Duty 4 great classic maps, Crash & Overgrown
Three additional well designed MW2 maps, Bailout, Salvage and Storm.
Bailout is really fun map to play with capture the flag gametype - think of 2Fort chaos from TF2.
Just like my Resurgence Pack review, these map packs are almost useless on PC version & you'll not be able to find any players with these DLC unless you're lucky to find a DLC lobby or you have friends that play & own MW2 DLCs. (Having these DLCs will lock you into searching for users with DLC)
Get console version of the DLC since the DLC management in the console version doesn't separate players with/without DLCs.
Basically, you'll be throwing your money at Activision if you buy these DLCs on Steam.