While the added delay may seem pointless for normal H2H (Double the delay for only occassional double hits), the OAT apparently stacks with Footwork, which has an independant delay. Basically you get OAT without any delay penalty!
Pretty awesome. Also has the added bonus of not needing to work on the "true" Magin OAT, as the DMG from footwork comes from the feet, not the hands.