I have to concede reluctantly that the Major System is superior overall to the Dominic System for the reasons that @TheHumanTim has mentioned. That being said, nothing limits you from learning both Systems. I’m not a Memory Competitor but if I were, I think I would strategize around the events in the Competitions with an ‘arsenal’ of different systems ‘fit for purpose’ for each event of the competitions.
Nowhere in Harry Lorayne’s books (and I think its fair to say he popularized,
if not commercialized) the Major System, do I see him mention the PAO System. Indeed, Dominic O’Brien, from his books I’ve read, only explained a Person/Action ¶ System, so I would be interested to discover how the PAO, PAOL, PAOQ, PAAO Systems have evolved over time. I have recently posted a ‘unique system for encoding playing cards’ which I consider to be a novel system for encoding playing cards, elsewhere on this forum, as well as a SCOC System (if anyone is interested in going down that particular rabbit-hole) too.
What I like about this forum is that we collectively can brainstorm and share ideas with one another, embellishing upon each others ideas, tweaking our systems, to serve our own particular needs and to do the things we want them to do. Never lose sight of the fact that any system is your slave and you are NOT the slave to any system. So in short, experiment with other peoples ideas, point out faults in other peoples systems in a diplomatic manner, if you differ from them, in a friendly and constructive manner. That’s what this forum is about. We can learn a great deal from one another in a collective pursuit of bettering ourselves!