Ok, I am seriously considering the P99C (comapct) for a carry gun. However, I am trying to understand the different firing systems. Can someone please help me understand the advantages/disadvantages to the QA, AS, and DAO? And why, if you have to rack the QA in order to cock it would you even want a decocker on it? Wouldn't that render the chambered round useless since it will be ejected when you rack to cock? The pros and cons of each would be greatly appreciated. Thanks in advance to those who can lend some info.