Having finished Episode Enyo, it's pretty god damn sick. Great music, great weaponset, great enemies(I especially like the big grenade guys and their laughing voice).
I do have an issue with the 6th level, in which it's barely a level at all. Just a reskinned Chthon fight except you get a wings powerup(basically you get to get 8 or so minijumps before you need to go hit the ground and any further jumps just slow your descent) and the switches are four sides of some spike like thing in the ceiling. Due to the powerup you get, it's extremely easy to just avoid everything(all enemies spawn on the ground and the boss throws very slow projectiles) and even if the platforms retract in between each switch getting hit, it's very easy to glide your way to hitting another two on your way down.
The mod does something cool for a Quake mod, in that it unlocks a couple of new game+ options. The jumping upgrade I've mentioned, and an alternate, stronger version of the dual smgs(which are more or less the workhorse in this game which I really like, ammo isn't rare at all compared to nails) which is a beefed up LMG.