I think this is a great book. It covers some very in depth rules on navigating the warp and astral telepathy. Which no doubt most GM's will be happy with. It has some extra careers for most explorers and new powers and ship to ship skills for astropaths and navigators. Some of the powers seem a little under-powered compared to what is already out there. However, they certainly have good roleplay aspects to them. A few xenos psykers are covered (with powers, equipment etc) and enemies of psykers. Although there isn't a huge amount of new explorator equipment there is an excellent section on familiars including creating your own.
In short this book is a must for GM's & psyker players (or wannabe psyker players.)
[5 of 5 Stars!]