I think that you need to increase your open to different levels and find out which one of them works out for you. You have been told that .5 is every risky but how can you tell if you have never tried. It may not work for others but it may work for you. You need to know what it is your trading plan and you need to stick to it and you can change at as many times as you can while keeping your goals the same. Change is good but not in most cases as it may turn into deviation and once you deviate, you lose focus on what you are after. If even after the trials, you do not notice any significant change then you can switch trading systems.