I bought the e-book. It's 173 pages long. The book mixes together friendly discussions of the logic of the system, definitions of bids, and frequent example hands. The bidding trees are roughly the complexity of (and very similar to, though cleaned up, and with more explanation)
Dan Neill's bidding tree for Fantunes, which the author cites as one of his sources.
The goal of the book is not to describe exactly what Fantoni and Nunes play, so the author has made occasional modifications (which it appears the author plays in a partnership of his), usually commenting thereon. For example, over 2
♦-2
♥ (artificial relay), the responses are modified slightly to make them a bit more symmetric, hence potentially easier to remember. The author also does not describe slam methods used by Fantoni and Nunes (e.g. Turbo), except in passing by way of suggesting that the reader instead use his/her own, and also leaves most of the system over 1NT and 2NT to the reader, with hints on key points to include to deal with the distributionally wide-ranging 1NT opening, for example.
The system is quite detailed and complicated. The opening is of course quite natural, and the responses are mostly straightforward, but thereafter many specialized conventional bids show up. There are occasional hints for simplifying the system where possible, but they're not very frequent. The reader can work on paring away more to come up with a bare-bones version, but it would take a lot of work to separate the truly-necessary from the very-nice-to-have from the fairly-useful and to come up with workable simpler alternatives.
Toward the end, there is a seven page summary bidding tree, as well as quite a few quiz questions, including a separate page of problems just on the Fantunes version of Gazzilli.
***
To add my $.02 to the discussion of imps per deal: It's quite difficult to separate system wins from bidding judgement wins. It seems entirely possible, even likely, that the .29 imps/board Fantoni and Nunes apparently win in the bidding comes largely or entirely from their bidding judgement.
Fantunes seems like a fun system, and I enjoy fun/different systems. I do think however that card play and bidding judgement are each quite a bit more important than system, at least once your system is reasonably well fleshed out.