I have an iPhone 6 with the advertised 16GB storage capacity. I've had the phone for several years and for the most part it has been a good phone except......... Although it is advertised as the 16GB storage capacity in actuality it only has 12GB. For future reference, is 4GB less than advertised acceptable, and if not what is an acceptable variation between listed and actual? I've had almost every iPhone since the first one came out except the 5C and one or two others and they all were a little less than what they were supposed to be. But 25% is just unacceptable to me. What do you think?