I had a quick three way trial with AK Jr, Plenue 1, and ZX2 today.
Plenue 1>ZX2>AK JR
Somewhat expected. Plenue 1 has a really rich signature(with headphone mode off, all eq setting off). I've never heard my Z5 play Norah Jones like it did. On the other hand, if you don't like warm signature, Plenue 1 might not be so great. ZX2, is also pretty good, though it's quite different from Plenue 1 too. It has it's own engine that alters the sound. Sound stage is...