is iphone 5 better unlock or worst ?

got brand new unlock iph5 mean it unlock any network 😕 , Is this ready update ? have latest update software 6.0.2 it feel worst when be update lost signal network ready took sim card and even reset and took back got replace 3 time😕 😮 still no diff then u said it i have ring up my network and reported network issue im still face my network issue 😕 no 1 want to give me a right answer i still have more 90 day