Hello dears. I used samsung Z4 for one month but it is one of the worst mobile phone in samsung series. I have used it and it is One of the worst os. it has many problems like, U can take a contact name or call from contact. It ll hang and then it will go to the process. I think it is Just waste of money. its baterry timing is also not good. its memory going to be full very soon just installing a few applications although it shows 8 GB memory but it is not 8GB in real. its camera is also not too good. I well suggest you not to bye this phone and do not waste your money.
thanks