Yesterdays I was farm T10 from PF (and finaly I got boots), no bard or ninja in party. And TP problem in half of last phase, when I played my "standard way". Then I stop use OP, on adds Flashes only and Fracture in Berserk only and have TP almost to then end.
Yes, Flash dont make real damage, but my overall DPS was higher with Flashes than with OP, because TP cost of OP. I know, that this is specifical situation, long fight and no bard/nin, but WAR must be ready for that situation and Flash, in my opinion, is important.