most usefull talent: reserve!

[GeneralGonzo]

Sureley an useful talent, I have to agree. Myself I use sometimes one extra slot also to replenish reduced stacks, but if you go tactically in the upper difficulties (hard and impossible), you should have some different troops in these slots so you can react on different enemies. I.e. archers are not so useful against undead (skeletons -> projectile weapons) whereas magic projectiles work better. So before the fight I exange my stack of archers with priests....