I really like the J12. The fruit are gorgeous wth deep red shoulders and deep yellow nose. The flesh is also a deep orange color not well represented in photos.
The flavor itself is reminiscent of the Julie/Carrie line, at least to my pallet. It is strongly flavored, very sweet, and has a sort of citrussey profile in a way.
I have not eaten enough of them to determine how it ranks vs the "greats", but for my taste it is right there knocking at the door.
The tree growth and size, precocity, disease resistance, etc, are all excellent.