I have a different reaction than most here. Maybe because I shot m43? The Olympus 12-40/2.8 was perhaps the best midrange zoom of it's era, and I got loads of use out of mine backpacking around Europe. This new Nikon is slightly lighter, zooms further, and all while covering a sensor twice the size. In low light the Olympus might barely manage a tie, and in plentiful light, on a Z7, the Nikon would go soaring ahead.
If the quality is close to the Nikon 24-70/4, I'd gladly trade a little bit of aperture for the 150g less weight and 105mm. I usually stop down during the day anyway, and at night, f4 doesn't feel adequate to me to begin with.