I guess I'm the odd one here. I never think tech in a backward mindset. meaning... I see what I may be looking at 2-3 years from now and with 4K, AR, and VR360 being the next big thing, It is important to be ready with the hardware that can perform. A backward mindset still views these smart phones as a walkie talkie with text and that's it. They could be happy with a flip phone with text capability and if it was easy to use, ability to look up things on the internet. Slowly this crowd is getting used to the idea of a camera in his walkie talkie. I must say that my wife fits this profile. She has just gotten used to the idea of a camera in her "walkie talkie" this year.
Some here obviously consider cost as the first requirement to meet, setting a limit and not exceeding it, then will upgrade again in a year. I'm not so sure that saves any money but it does keep you under the state of the art by backward thinking, buying a year old technology just to save a hundred $ at purchase. That's fine if the latest new thing is of no interest until it finally dawns on you that it's cool. Like my wife, who just this year finds having a camera all the time is cool. She used a Blackberry up until she retired too because it had hard buttons for a key pad. I see those who complain the loss of the home button as a "Blackberry mindset."
The ram of 128GB I have in the 6+ is never used, ever. But that's because I find the camera inadequate for my work and only use it as a note pad when shopping or those rare times I need to take a picture and don't have a real camera handy. The new iphone with dual lenses and OIS in the X plus the AI processing of back light balancing is real interest to me. So I know if I plan to be shooting 4K video with the X, I won't bat an eye of forward thinking to 256GB.
Just for comparison, On a 3 hour excursion I shot 4K video and filled a 128Gb SD card. I might only use 10% in my edited project but I would rather have it and not need it than need it and not have it.
Not only will I pay the premium for the X, I see the need for 256GB as I start using these advanced technology features in the X. If Apple allowed for plug in micro SD cards, I would buy just a 64GB version with a stack of cards for storage.