Out of the few participants who were willing to pay $2,500 or more for their next bin, most wanted to see a new, innovative design rather than incremental changes to what they already had.
"A new class - lighter and more compact".
Ergonomics for me is weight. Don't know if changes to prisms would save weight because not sure of the difference.
Bigger sweet spot would help I suppose but not if sacrifice field of view. The field of view in the 7x42 is not sharp to edge but it is usable to see movement and the center appears sharp to me.
Another question "rolling ball" effect. I pan a lot with a scope but hardly at all with bins. Maybe I don't do it right but I look for bird with eyes then move bins. I do live in NE US so most birding in forest edges and maybe that makes a difference.
Mike
I would happy enough to see several incremental improvements in the optics.
First, a different design choice in the off-axis characteristics of the eyepieces. I wouldn't object to SV like performance, but as others have said perfectly sharp edges are not really necessary. The weakest thing about the current FL's is astigmatism beginning at 12-15 degrees off-axis.
Second, better control of lateral color.
Third, an increase in the bandwidth of the T* coatings, which have good peak transmission at green/yellow wavelengths, but roll off too quickly in both the red and the blue.