I’ll stick to the topic - which is 40k roleplaying.
I ran Dark Heresy for 2 groups and thoroughly enjoyed it. There is a darkness to the system and a bleakness. It’s very good for running Cthulhu style horror mystery set in the future.
The multiple Dan Abnett inquisitor books added a brilliant context which most of my players had read and the setting heavily drew on these for inspiration and themes. I thought the published adventures had a lot of promise. I recall a savior cult that was using captured psyker brains as a mind expanding drug, capture in a beast cults fighting pit, daemons bound in clockwork, and an auction for evil power groups. There was a lot to creativity in Dark Heresy that I don’t think the spin-offs ever quite matched.
I found the rules fun and interesting but breakable by a player that wanted to. I think the social contract is absolutely central and you need to play with folks mature enough to get into the spirit and not to try and eff it up. Melee combat can quite quickly become much better than shooting which feels slightly off to me. Psyker suffer from the old edition problem of being very poweful and in constant danger of blowing up.
Shout out for Disciples of the Dark Gods. It is my favourite Enemy-Sourcebook of all time. Thick and dripping with amazing adventure and campaign ideas.
Shout out for Wrath and Glory’s published adventure - Duty Beyond Death - which features a corrupted Servitor manufactorum that’s has gone silent. It’s an absolutely stunning module that absolutely captures the feel of the setting better than any other I’ve seen. Very cleverly written. It part of the Litanies of the Lost adventure compendium. This adventure will be adapted to the next futuristic campaign I run -
whatever the system.
Interestingly there is a third system for 40k that has just been released called Imperial Maledictum. It uses the full WFRP chassis with the additions needed for a futuristic game. The career system is changed but otherwise there are a lot of similarities. I’ve only just bought it and my impression is that it is a very robust system. Improving on the 4e WFRP which I already like. I think Imperial Maledictum using the product ranges released for FF’s products would be pretty darn awesome.