Isotta 45° Full Frame Angle Viewfinder vs inon viewfinder ?

Hi everyone,

I'm trying to decide between the INON 45° viewfinder and the Isotta viewfinder.

The price difference is substantial — around $1,100.

Has anyone used the Isotta viewfinder and can share their experience? Is there a noticeable difference in optical quality or overall usability that justifies the much higher price?

Thanks in advance!