I guess because I have never done any speed runs, only pulling one mob at a time, that's why it doesn't seem like I always need to do it like the people I was playing with said. What I will usually do is shield lob a target, flash a couple times to attract the rest of the mob, then go for RoH combo. If I see the aggro meters getting to 75% I will flash again, but it seems to rarely to get that high. As long as everyone is on the same page and attacking what I am attacking then I really don't need to flash. Though I am guilty of not marking targets the way I should be, but most seem to realize what I'm going after since I always use Shield Lob at the start of a pull. The blind aspect of it doesn't really seem to do too much.

So it seems more for multiple mobs and end game content, which I have not reached yet. To have to be keep using it.