I have flown JQ long haul in both J and Y (that was a mistake) as well as QF Y, PE, J (and F) so can compare them all. Like others I found JQ J to be superior to QF PE - better seat but food and drinks similar.
We did OOL-NRT-OOL on the max bundle to get the status credits because it was a revenue booking. Not sure I would would use points for JQ J, even with the 20% discount on QF J, if my recollection of how it is calculated is correct. Clearly the lack of fully flat bed, and not quite QF J leg room, makes it inferior to that product. But I was pretty disappointed with the QF PE due average seat and pathetic leg room, barely more than Y. Food and drinks fairly close across with QF J slightly superior if you want to enjoy all courses and a better wine selection.
We did try JQ Y for SYD-HNL-SYD on a very cheap fare a few years ago (before I discovered AFF) and I vowed never to do that again, especially with a toddler. A few years later our then 5 year old daughter had a great time in JQ J to Japan, but thanks to AFF has become used to flying J, a problem I am sure many of you share.
One thing to watch out for for on the JQ 787s if you are sensitive to light is that the electronic dimming of the windows does not completely block out the sun's rays, which becomes quite annoying when that great blinding orb is low in the sky and shining straight in from the side when you are trying to sleep or watch a movie. We also had entertainment system failure on the outbound flight to NRT but our iPads were fully stocked and paired with Bose NC headphones made it a minor issue.
Overall go with JQ j for a good option between QF PE and J, provided the price is right, and a good source of points and SCs.