The reason it is more viable now is that wars have to be more capable offensively with Trixters around. From my limited work with the skill, Down and Dangerous gives some offensive boosts in addition to the knockdown resistance.
It doesn't give any offensive boost, nor it protects against knockdows (why would it, the point of the skill is to keep the gladiator's performance decent when he's on the ground). Even if it did, it still requires a knockdown to activate which is not something under your control. And it would be very strange to have offensive bonuses while at the same time the skill "helps to seize the opportunity and stand up more easily", effectively cancelling such bonuses. You wouldn't train a gladiator with that skill, would you? If not, let's just drop this, it's pointless.