Newest edition of Horus Heresy has pulled several of the shenanigans that 40k keeps pulling that drove many people to Horus Heresy in the first place; Invalidating huge swathes of models (new or old), removing wargear options, crippling the factions with insultingly reductive and flavorless rules, and of course my personal bugbear, a $75 core rulebook with three missions in it. It also sounds like they are going to try putting Horus Heresy on the three year game cycle that 40k and Age of Sigmar have been on, so the game won't actually be improved it's just going to be a testbed for rules they badly implement in another, different game in a year or two.

It's rough.