Kraken is definitely not that bad but it is risky because of the high knockback and also taking away from your ability to finish off portals, paint, and clear out an area. I mainly use it in situations where I think I might get trapped and die if I don't get out of there fast but if I get the chance to switch it out with Tri-Strikes, Zooka, or Booyah Bomb I do switch it. I would probably put it in good, at least in an okay tier.