RDM BiS?

[Powercow]

Yeah, but wouldn't the 10% increased base damage still have a chance to dHit / crit / dCrit? I think it's less about stacking a stat at the expense of others and more about keeping stats relatively close together with a preferred stat that's above the rest.

This guy's got the right idea. Right now, unless you're a Bard (and possibly monk, the bonus chakra generation is usually grossly overestimated), DH is that preferred stat of those 3 secondaries. The wildcard secondary is Speed, which varies from incredibly strong (BLM's best stat) to incredibly weak (NIN's worst, by far.)

In a vacuum, DH is better than Det. However, once you hit a certain DH threshold, Det will be better. But then Crit gets better once you have more DH and Det. That is, until you hit a certain Det threshold, then DH... well yeah, those 3 stats go back and forth jockeying for first place. We're already at a point, in the first raid tier, where stacking DH exclusively won't result in the highest possible DPS -- though stacking DH exclusively is also impossible so it's a moot point.

Think about it like this: what's better, a 30% damage increase, or 15, 10, and 5% damage increases?
1000 dps * 1.3 = 1300 dps.
1000 dps * 1.15 * 1.1 * 1.05 = 1328 dps.

The weird thinig is that Crit has accelerating returns, which is something no other stat has. It's why Crit was so god-tier at the end of HW. However, we're not at a point yet where Crit's accelerating returns are strong enough to overpower the other stats in terms of raw contribution. Given how slow secondary stats are scaling up from 300-340, we may not reach the point this expansion where it's "CRIT OR GTFO" like we did in HW.