I'm pleasantly surprised by how good the megadap is even for video af. I filmed a music video today with the z8, megadap and the zeiss 50 f/1.4 and the af was impressive.
I tested the Megadap today with my Z9. I downsized the images to 4000 pixels but these are SOC. My sense is the megadap is good, but a bit less keepers than the native Nikon Z. Keep in mind these are quick off the cuff photos I took just outside the store / in front of my place
Sony 70-200 GM II pictures 1-604
Nikon 70-200 Z pictures 605-754