yeah, im gonna have to say get the 20 att, hold the 31 prayer though, eugh :S
getting that 20 att unlocks such a better arsenal, and if you still wana you can use your obby maul for kos still, and you'd be more accurate with it too hah.
20 att > 1 att, esp if you use your corrupt weps, they are the best low lvl koers there are.