Board Thread:R2D - General Discussion/@comment-25888702-20150319123444/@comment-25394521-20150319134008

First of all, Katana is basically an upgraded Chainsaw with the ability to run but the disadvantage of stamina. Second, Katana is really handy with Strawhat, and real OP without a primary and ENRGY drink.

But I recommend Chainsaw for players who want a primary. Chainsaw basically has the same gameplay as Katana, but without running and no ammo and stamina. Chainsaw has the invincible and undebatable ability to gun hop. With AK-47, Flamethrower or Minigun, you can jump even to the top of the clock tower in ArcadeTown with ease.

To summarize, they both have the same gameplay because it's just "rann infronts of a tenk or hords of zmabis and slice and dice". If you want a primary, go Chainsaw. If you want diverse gameplay, go Katana.