On trash mobs in dungeons, it depends on how well geared the DPS is. If they're well geared, I stick to the trusty Flash --> Circle of Scorn --> Halone combos on whatever needs it, throw in additional flashes here and there as needed, and then start using Royal Authority and Goring Blade as enmity permits. On bosses, it depends on how well the healers are geared. If healing isn't an issue, I tend to use Halone combo sparingly, sometimes just to throw the Strength down debuff on the boss for some mitigation, but mostly I spam the Royal Authority combo, and do my best to keep Goring Blade uptime at 100%. When DPS is really well geared, with full Asuran armor and i190 weapons, I'm pretty much still just tanking like 2.0, lots of flashing and Rage of Halone combos nonstop. I've gone back to marking mobs so I can catch a break from trying to keep up threat on 5+ mob groups without becoming a Flash bot.

And I really wish we had a trait to reset the Circle of Scorn timer, or shorten it further. I wouldn't mind more AoE damage+threat, and less almost-useless blind debuff.