Highlights to look forward to:
Quad HD Triluminos display
4 GB of RAM
Running Android 5.0 Lollipop and its 64-bit kernel
A new camera sensor and two more lens elements for collecting more light. Dual LED flash expected.
3420 mAh battery
Z4 Ultra expected to feature a 5.9" screen, not a 6.4'' panel
Lower 16Mp Camera for Z4 Ultra. Z4 Expected to have 20.7Mp.
Source indicate the Z4 & Z4 Ultra will be equipped with an 805 generation