For me personally I cant stand Rak Gul, Stysixis, and Kroot as the "plugged" in Xenos for RT...
I replaced them with Migo (from Lovecraft), Neogi (from D&D), Yautja (Predators), Trikreen (again D&D) instead - I was wondering if I'm the only one who doesn't like the Rak, Stys, or Kroo?
Funny enough I've aimed for a more "weird" than "action" oriented campaign fluff for me game; on that note I heard that the original warp had no association to Hell-like experience / things - rather it was more twilight zoney...
Morbid