I love playing this mod, both sides are very fun and it keeps me engaged.
I kind of wish the hellknight replacements were SLIGHTLY less agressive in their jumps, because they can quickly block off narrow areas or teleporter entrances without giving you much of a chance.
I think the enemies doesn't work with Hexen, as I loaded it with Hexen.wad with the latest Gzdoom executable, but I also had tried it with Doomrunner.
Amusingly, enemies spit out red gore you would see from spiders usually, and the beginning Ettins get the speed of the spider critters (I presume other enemies might similarly get speed changes.).