I think the new update is much better than the older one.
Swiping through the screens is much quick.
It has nice contrast and vividness.
The icons have been replaced and look more 'organised'
For me the biggest advantage of the Z is the big screen. Playing a song and viewing the artwork is something I never enjoyed before. (always never cared about artwork). Also I get to play some videos of my kids playing so I can watch in landscape full screen. To me. its the ALL-IN-ONE media player and maybe I wont see another like that in a long time.