There is a sizeable difference between my Nikon 24-70 2.8 F mount and the 24-70 f/4 Z mount. And because the body is stabilized I can shoot as low as 1/30 which makes up for the slower lens. I haven't seen the 2.8 Z mount though, but all the Z lenses are supposed to be markedly lighter than the F counterparts....... Well, B&H says my older version of the 24-70 2.8 weighs 2 pounds. The newer, VR version weighs 2.4 pounds. The Z mount 2.8 equivalent weighs 1.75 pounds. My f/4 Z mount weighs just over 1 pound. So that can be a lot of weight savings, depending on which lens you are replacing.
I haven't gotten the hang of focus peaking yet. I tried a bit yesterday to figure it out but didn't get far. Since I shoot the majority of my macros handheld, I'm not sure focus peaking will benefit me much but I think right now it's more user error. I can't seem to get to the same screens I see in tutorials, so there's something big I'm missing.