Thank you Ricoh for the new GR IV premium compact, but I’m going to stick with my GR III for now – here’s why

Ricoh’s new GR IV is a minor update of the GR III, equipped with a new 26MP sensor, a new 28mm f/2.8 lens, and various design tweaks. Is it worth upgrading for, or should you save money and opt for the GR III instead?