a7iv vs. a7riv(a) for birds

[number_5]

From what I read, the a7iv seems (maybe?) to have better AF, and obviously, the a7riv(a) has higher pixel count. For those with real world experience, please chime in. Will pair it with 100-400 and video is not a priority. TIA.

 

[mattcamera2021]

I don't have a a7ivR to compare too... but the bird eye focus on the a7iv is amazing