Some thoughts:
1. I've grown to hate the concept of it, and what it sells and how this filters down. Too many seem to think it's a "new" level of youth football that sits somewhere between "grassroots" and academy football. That's nonsense - it's grassroots football with higher (unrealistic) expectations and higher costs.
2. Their admin is somewhere between poor to non-existent. Once you get away from "central venue" fixtures (those being mini-soccer), you will get no support, advice or even a response to any queries/reports etc and appointment of officials is, in my experience at least, down entirely to the home team - there are no referee secretaries or league adminstrators that I'm aware of.
3. Whilst I think the supposed gap between JPL and the higher divisions of Sunday youth football is pretty negligible, the standard is usually quite high and given the expectations their marketing has created, it can be a decent refereeing test.
4. One difference I do find is that the perceived higher level and expectations/pressure from parents tends to mean there are more challenges that require disciplinary action than you'd tend to find at more mixed-ability levels, and managing "what the game expects" versus what the LOTG require and protecting players can create challenges.
5. All that being said, most teams I've come across do teach the right ethos and enforce it, and are easy to deal with but it does also tend to mean that the outliers can be pretty awful to deal with, though they are the exception. My worst experience by far with a coach/parents was a JPL match, and the subsequent WGS extraordinary report simply disappeared into the ether.
In summary, I wouldn't put you off it if you can find a local club with the right ethos and good admin, but don't believe the hype.