As a person who played AoS and was impressed with their battle tomes this is next level over even the Kharadron book which is fantastic. Granted 40k is slightly more complicated. So I am impressed, but not surprised. GW has mostly been hitting it out of the park in particular their AoS battletomes. I knew they would bring that same excellence to this one. They also like to keep them consistent. So I would expect a matching in content to the SM book for most armies.
This makes me interested to see more fleshed out Septs at last. Not only rules but fluff.