If you're a speed running tank, don't just sit there and let mobs hit you over and over with their faster run speed while only having 1/3 of them held to your name. It makes it impossible for healers to cure, refresh stoneskin / adlo, etc. without also dragging near instant death our way once the pull settles. Shield lob / Tomahawk things as you run, or learn the placements needed to drive-by flash / overpower. It's the difference between someone having to play catch-up healing all pull long or someone having the circumstances needed to join in DPS with some potentially huge numbers.

And don't hold one hale and healthy mob while running to the next group. It kills the natural regeneration ticks tremendously. [/pet peeves]