Thank you. I asked because my results with ticks were very different but that was probably due to my implementation.

Have you also tried implementing First Strike system? It's something that has been promoted by the same guy - Joel Rensink AKA TheRealThing. It's supposed to be complementary to ONS as it trades from monday to friday. In this link, there's also .pdf with the rules for download: http://systemtradersuccess.com/first-strike-trading-system/