I have it and have read it. Not tried it yet.
It's a very nice book chock full of campaign ideas. It lets you play a 'ladder' campaign (basically just a linked series of games) or a full map campaign with secret objectives.
It's also got a couple of new scenarios as well.
It does for SP what 'At the Sharp End' and the pint sized campaigns do for Chain of Command
If you like Sharp Practice and want to be able to link the games together, then get it. It's a bargain.