How do you think these two will compare? If we assume the damage reduction part of tenacity is going to be in the same boat as parry, nice but not needed, then it comes down to the damage increase portion.

If it scales worse than det, then it will go the same way as parry, avoid it unless SE puts it on everything so we can't avoid it. If it scales better than det, then the same thing will happen to det.

I suppose that with the first situation at least it's not as bad as parry, even if it has no impact on how we choose our gear.