They are probably good for Act 7 since there are so few fights per path. Even if you don't have suicide-friendly champs as such, they won't whittle down too much over the course of the quest. In the gargantuan Act 6 quests, though, I'm not as sure. Obviously suicide-friendly champs could still use them to great success, but less suicide-friendly champs would probably struggle a lot without a lot of health potions.All in all, I like using them occasionally because they make certain champs infinitely better (using Corvus, Namor or Omega Red is night-and-day with and without suicides), but overall I just like the freedom of throwing a lot of special attacks whenever I want too much to have those masteries on for too long. Special spamming is how I enjoy playing the game and suicides just don't allow that.