Hmm,,, good enough reason for me to save my money and waitIf camera is your concern, upgrade. Else leave it. nothing so much great except the camera part.
my opinion, stay with ultra and upgrade to ultra 2 or z3 according to the rumors sony is gonna change the design from z3. high probability that sony realese another one between Q3-Q4.
Little is an understatement.Sony Xperia Z2 is definitely much more powerful than Z ultra but its little bit overpriced.
My recommendation - Wait for LG G3.