I always mark, but I watch for DDs who can't be arsed to target the marks.

Unfortunately, in high level dungeons, I often find myself forced to resort to cycling Fast Blade -> Riot Blade -> Flash over and over again, because the DDs can't be arsed to focus the same target. Since the patch, I also toss in a circle of scorn from time to time, as it now carries an enmity boost as well.