Field of view. I couldn't use the atx95. I found myself regularly wanting to zoom out more, or spending all my viewing trying to keep the (moving) subject in the view.That's interesting to know. Its curious that Zeiss glass at that level should display more CA than the Swarovski equivalent. I wonder if other people have that experience, too.
Out of curiosity, why did you make the change from the ATX to the Harpia?
To the point I wasn't actually watching/identifying birds.