優點:
- fast
- the most stylish mobile in my opinion
- very nice camera.  It can take very good photos even in the dark.  
- with a front camera of 5MP, a huge improvement from Z3.  Now I can take a selfie with decent resolutions.
- I now can charge it with a mini USB alone.  For Z3, you have to either get a separate charging dock or open a small flap on the side.
- the SIM card slot is now in drawer style.  You can just pull it out, put the SIM in the drawer and push the drawer into the phone.  For Z3, you'll have to carefully struggle to pull a tiny SIM holder out with tweezers, put a tiny SIM on the tiny holder with tweezers if not fingers and struggle to push the holder back in place before the phone can finally detect the SIM.
缺點:
- It gets warm once you have used it for a while.  The longer you use, the hotter it becomes.
- the battery life does not last as long as that of Z3.  Z3 can really last for a whole day even if you use it during the day often.  But Z3+ can only last for a whole day if you only check messages.  Very disappointing.  
- the contacts app does not show icons of all accounts that I have synced like Samsung does.  In Samsung, if a person has his/her Whatsapp or Skype, a Whatsapp and Skype icons show in his contact page with which I can contact that person by Whatsapp and Skype directly by clicking those icons.  But Sony's contacts app cannot, I have to exit the contacts app and go into Whatsapp or Skype.  not as convenient as Samsung.
評價:
I was an user of Z3 which was almost perfect except the front camera the resolutions of which are very low.  That was why I get this new model even if there are not much improvement in the spec.  
Unfortunately, the battery life is disappointing comparing with Z3.  I guess it has something related to the heating.