I love the dark defender set. But I find that I almost never use tar patch or darkest night. They take so long to apply that I just do not find them worth it. Tar patch I can use from around the corner, so I use it on builds that have a rain I can drop around a corner,. Darkest night I use on AVs and that's basically it.
My problem is that the start of the fight is usually the most important. If you survive that, the rest is more of a grind. Fearsome stare is great at the start - to hit debuff and fear and it applies quickly.
I play almost exclusively in the 10's and 20's, no 40+ game, no IOs. So this is not a question of the enemies being defeated too quickly for debuffs to matter. This is a question of the debuffs taking so long to apply they miss the crucial start of the fight and are not worth activating compared to other powers I can use.
Are people using the long activation (over 2 second) debuffs on dark, rad, and other sets in normal gameplay?