The first Delta Green supplement for CoC was an original take, spy vs. cultist in an action-conspiracy setting. This set of books is a tedious rebadging of the 40-year-old CoC game in fed land.

The PHB goes into excessive detail of all the US federal offices the PCs will not come from, the GM book goes into tedious historical detail as to why all the interesting adversaries of the original supplement are defunct and there is nothing to play against any more before replicating the CoC bestiary with a DG gloss. The system is the 40-year-old CoC with some updated tweaks.

I am glad i bought this as a discount pdf, I would have been angry if I had shelled out £70 on the books.