Since "Liber Xenologis" is not an official Games Workshop publication, but rather a famous (often attributed to the Bell of Lost Souls forums or similar community efforts from the mid-2000s), reviews of the PDF are fascinating time capsules.
(as a historical artifact), 3/10 (as a usable tabletop rulebook). liber xenologis pdf
: New insights into the Orks, Aeldari, and T'au. Since "Liber Xenologis" is not an official Games