As the title says, my JAL experience was ok - neither good nor bad. As a Premium Economy flight, it delivered the leg room, but the seat was not particularly comfortable, the pillow flimsy, my video system had a few problems, and I found the meals acceptable but uninspiring.
I was hoping to start my trip with some Japanese inspired meals, but PE shares the same menu as Economy, and with Spaghetti Bolognese as the default main meal for one occasion, the menu was, overall, disappointing. They need much more of a Japanese theme to their meals.
There was no priority queue to board the flight, but to my surprise the ticket did include access to the Qantas Business Class Lounge in Sydney, which was a great start, as we felt very relaxed and somewhat privileged!
I'm not sure I'd fly JAL again, as it was clearly inferior to my PE experience with Cathay Pacific in late 2017.