Disclaimer: This post deals with matters of opinion! I am not stating facts, and I don't believe that I am! I recognize that this is just my own opinion, so please recognize that, too.
I hate the belief that JP pts are "more efficient," "more patient," "get better exp," etc etc. It's just not true. I've been in some JP pts, and I've been in some NA pts. I've also been in pts with people from France, Germany, China, Singapore, Malaysia, and all manner of countries all around the world. There's nothing about a country that makes people there any better or worse at ffxi, that's just ridiculous. Whenever I play, there are good and bad pts. So, putting the bad pts aside, I can easily say that I've had many good NA pts that are just as good as the best JP pts I've ever been in.
So, my view on JP pts? Well, I think that JPs have a different playing style than NAs. They do like to take a long time to form pts, but the result is that they often get a good pt setup. It seems like they will wait for exactly the classes they want, so I often end up with a brd in my JP pts, which is great! The downside, of course, is the experience that you could be getting in the meantime with a less perfect pt is lost. NA players tend to do their best with whatever is available at the time, even if it's not quite perfect. The result of this is that maybe you get a tiny bit less exp per battle, or they last a little longer, but you get started much sooner.
In my experience, JP pts are different, but no better or worse than NA ones.