Is TBN a bad skill?

[ArianeEwah]

Also people say it's "DPS neutral." Only when accounting for the DRK's personal DPS. As long as it saves your healers a GCD, that GCD goes to damage, and that GCD is pretty much at the strength of the Edge you lose if you screw the pooch. Raid DPS wise, it's an indirect gain, when used properly, and a bigger gain if you can use it so that DPS may bypass disengaging/keep uptime. Plus, if its use saves someone from death, this is rare, but if it does... that loss prevention can make or break a clear.

The thing about that is... in most cases IT DOES NOT save a GCD from a healer. And that in probably more than 90% of this (end) game's content. Maybe an oGCD, but then its a wasted resource anyway. (WHM might be an exception bc of their lily/heavy GCD healing design)
Even if it does save your healer a GCD compared to... let's say GNB: GNB DPS is no doubt higher than DRK, but it's a safe investment into dps. TBN is not, quite the opposite. As I said above, TBN saving a GCD heal is already unlikely. Using it only when you know it will break, is indeed "DPS neutral" at best. You can experiment in duty fights to optimize TBN uptime, and still make sure it breaks. That still doesn't guarantee it will bring your healers more dps. This is a gamble with high risk/effort, low reward.
The only (not even a) handful duties -where TBN shines- are Ultimates. Ultimate AAs, raid wide etc. deal so much damage that the shield breaking during its duration is 99% guarateed. So much, I would even say it's overpowered.

But is TBN bad or good? The shield and its short CD would be overpowered without the mana (gauge) cost. But is the cost and risk of losing it bad or good? Neither, imho it's just bad designed. It does what it is supposted to do. Overmitigation will result in (own) dps loss. Which in theory should give healers more time to dps.
The problem is the practice. Healers at lvl 70 (at which TBN is unlocked) onward have so many oGCD healing abilities, overmitigation with TBN will most likely NOT result in higher healer dps. And the occational usage of TBN (e.g. 1-1½ uses/min) with a guaranteed break doesn't really grant more effective mitigation than any other short-CD mitigation.
Its good points lie in Ultimates and early progression. Less defense + less HP in early progression, while healing power is also lower -> more likely to break, yet great HP save. In contrast to the other CDs, TBN doesn't actually scale well. While the shield increases with your (or others) HP, so does defense. Thus TBN becomes harder to break in situations, where it did before. The healing power of your healers will also increase, which makes them less dependent on GCD heals by nature.

So again: Bad or good? Neither, yet both. Good as early progression tool, bad or mediocre as standard CD. High risk, low reward. Overpowered in Ultimates, yet bad designed. Great, and the reason DRKs toolkit as a whole becomes mediocre instead of just bad? The shield is necessary, but the design is annoying. Pick your poison.