The A7C II has a larger 33MP back-illuminated CMOS sensor than my older A7C, but what actually deserves attention are all the small physical changes to the system.
I love having an electronic viewfinder. It makes me feel secluded and in my own filming / photographing world, which helps me get into the storytelling zone. And with more and more Sony cameras — cough, cough Sony FX30, ZV-E1, and ZV-E10 — ditching this private, tiny screen, I am very happy to see it getting a small spec bump here. The difference is only .11x magnification from the original A7C, but it makes a large difference in practice. Settings are more readable and less eye strain ensues.
The A7C II’s grippier leatherette and slightly deeper handgrip allow for a more secure hold when larger lenses are mounted. And although my hands are that of a child’s, I agree with Antonio that these cameras greatly benefit from the add-on pinky grip for long-term handheld use.
And lastly, the cutout for pulling out the screen is now on the bottom, as opposed to the top of the screen, there is an added custom function button on the back, a physical switch for changing between S&Q (Slow and Quick mode), video, and photo modes, and the exposure compensation dial spins infinitely and has no text on it. Of these changes, I am most excited about the latter. I instantly switched that dial to white balance and was incredibly happy to never think about exposure compensation. Give me all the customizable dials, please!
Otherwise, the A7C II doesn’t feel all that different from the original A7C. In fact, it is my favorite Sony system for its small size, great specs, full-frame sensor, and EVF. But for Mark I users, I would hold off till the next generation. It isn’t so much of a jump in quality that an upgrade is needed.