I understand what you are saying. However, perhaps JAL Business class is so much better than AA Premium Economy that I will land well rested and will be able to make it through the day just fine. If that flight landed later than 8AM I wouldn't be asking this question as it would be a no brainer, but 4:30AM is a different story.

But they have that flight for some reason, right? Or is this aimed at Japanese salarymen who land 4:30AM and go straight to the office?