I have XT1053 DE. I like many aspects of the phone, but not that it was designed to be a throwaway. When I have to replace it, here are some improvements I'd like to see:
Fix the bug where it can't see or connect well to certain older phone repeaters / signal boosters.
Category 6 LTE with at least 4x4 MIMO and 64 QAM.
Removable battery. Motorola can sell 2nd / replacement batteries and more than 1 customized back to many customers.
Rubberized and deeply grooved / patterned back to reduce slips and drops.
Much stronger glass. Do Motorola's product designers have kids, or what?
Wireless charging. The female part of the USB plug is a weak spot, as well as those flanges on the male part.
Less than 4.5" screen at 720p. Improve the color and brightness rather than increasing size. This is a telephone, not a book reader. It has to fit comfortably in the pocket and hand. People who want higher res and bigger screens can cast screen or hotspot to a computer.
External micro-SD slot. I want to be able to carry around lots of videos of my kids, without otherwise impacting performance. Market it as the family-friendly phone, and let other companies have the tiny niche avant garde market.
Camera with 3-axis OIS.
Front-facing stereo speakers.
AM/FM radio.
Too sleepy to remember the others I've been thinking of.