You're right about the small price difference. I had missed a connection for a D class award ticket and had simply asked the agent for a ticket to a different airport. I didn't even realise that I had a J seat until I asked the gate agent about upgrading and she told me I was already seated in J . Mind you, when I boarded it took a moment to realise I was in J. I've not checked, but the price difference couldn't have been more than $20 or $30 from full Y. For that you also had their lounge bar open before 9 a.m. and an in-flight bar service. A little too early for me, but I suppose it's one more perk.

On thinking about this, I'm at a bit of a loss to understand what purpose J class serves for these flights, or what the rationale is. The extra revenue per passenger is not enormous, there's no extra space (my main reason for preferring J), and the back of the front cabin is a long way back, so there's no fast exit. There is metal cutlery and I assume slightly better service, but that's hardly a justification. Obviously it works, because there were a lot of people in suits in the front cabin, but it does leave me puzzled.