I should have mentioned that there are people who feel blitzer's roll is useful, but I have yet to see the situation in which that occurs myself. Since it lowers TP gain, it'll kill any x-hit setups your DDs are using. Since it can't break the overall haste cap, it will have 0 effect on an all-out zerg for people who have SV marches, haste, full equip haste, and dualwield/martial-arts/hasso. Even though it lowers YOUR TP gain per swing, the monster you're hitting will get just as much TP from you as it would if you DIDN'T have blitzers roll on. Finally, on a jackpot roll of XI, it's ~12.1% delay reduction, which is weaker than victory march with a +2 to marches (bards can get +4 to marches now with gjallarhorn and AF3 gloves, pushing victory march up to 15.6% haste). Hell, jackpot roll on WAR roll with no WAR in the party is 18%. If you get the job bonus via hat or having a WAR in party, it's 24% (twice as powerful as blitzers, plus it can proc during WS, plus it doesn't decrease TP gain, plus it stacks even if you have maxed out haste).

Those are the downsides to blitzer's roll. Granted, I didn't take the effect of haste stacking into account, but that's because its my opinion you either have lots of haste and don't need blitzers because you're already so close to the cap, or you have almost no haste in which case blitzers will be poo. It is not useless, but it has a lot working against it, and I have yet to even think of the situation in which it would be useful over another roll. Well... maybe a party with 6 corsairs.