If DET stacks "poorly" than so does every other 2ndary stat. Its like when people are saying that Skill Speed only gives 0.01 sec reduction, as if the equivalence in CRT gives you 100% crit chance or something. The truth is, the same equivalence in CRT gives you a 1-2% chance increase, which, when you do the math, is actually be less DPS than the 0.01 sec reduction on the longer fights (for certain classes).

I like skill speed for war, cuz it means faster wrath stacks. Its not gonna be hugely noticeable but other stats aren't either. Personally, I think you should test the stuff yourself but if you don't want to, you can easily goggle the priorities or check Reddit or something. Even though I often don't agree with them, they do often give detailed reasonings.