[Kromm]

As others have noted, the idea is that you don't take the disadvantage if you don't plan to play it. Playing it means doing crazy stuff every turn without bothering to roll to resist save in those rare circumstances where that's super-important. The disadvantage is actually worth more points than Berserk (-15* vs. -10*), so it's generally worse.

That said, there's room for interpretation: "All-Out attack or engage in some other kind of near-insane, suicidal behavior." As the GM, I've often been fine with the latter in lieu of All-Out Attack. For instance, in a medium-range gunfight, taking Move maneuvers to cross the fire zone so you can use your kung fu skills . . . well, I think that qualifies. So does taking the time to Concentrate on turning into a werewolf or activate your super-strength before you go nuts. So do a lot of things that use maneuvers other than All-Out Attack, if they're necessary to set up All-Out Attack or exercise your craziest option.