So I've had plenty of time to assess the A7R IV now, and overall it's an incredible camera. IQ is stunning, ISO performance is excellent and I've got no qualms with AF performance. However it's not all rosey, The inability to change many settings when the card is being written to is infuriating and actually caused missed shots/opportunities yesterday. And today I was lucky not to mess up my landscape shots as I've discovered that the memory custom settings don't save the AF with shutter (BBF) setting.
I just don't understand why camera manufacturers can't get these things right. They may seem like small issues but they become really frustrating. That being said, overall
I'm happy with my choice to swap to Sony