Apart from the scenario (which was some sort of underground battle... which didn't inspire me to play it.) all of the stuff in it is repeated in the main rulebook. It is nice therefore but not strictly necessary.
A PDF of the whole rulebook would be just as good, since the softback bindings soon gives up the ghost, when referring to the weapons tables. IMHO the rule book should have been split into two with the weapons tables as part of the seperate booklet.