Shield swipe has minimal impact on tp management. It costs 10 less tp than you regen in the same period of time, and given the damage you lose from letting goring drop or delaying your next royal authority by that much I'm not certain its 'worth' it. Its not 'trash' but its neither a dps game or a hate game (compared to halone). The times where its useful is maintaing hate while doing your GB/RA combo, but if you do that, your Rage debuff will fall off. In 'hard' content (raid" you dont want the rage combo falling off, and goring/ra is too good of a combo to keep going---> unless the rage debuff was extended, there is no gap to put in a shield strike until you have an absolutely insane amount of skill speed.