I wonder about some of the new optics technology and whether it makes much difference to the birdwatcher.
First, FL, ED, or whatever you call chromatic correcting glass. Does this make a huge difference in the image? I have heard that at typical bino magnification, chromatic aberration really isn't much of a problem.
Second, aspherical technology. This is supposed to make the image you see "flatter". I see the benefit of this for astronomical viewing. You want a flat image of stars across the field of view. But for birdwatching, you are more interested in a subject that is in the center of the field. A curved field of view might actually be more natural for terrestrial viewing. Also, curvature of field brings closer objects in the outside field of view in better focus. This might actually help the appearance of better Depth of Field.
Some technology, though, I see as being a very positive development no matter what your viewing interests are, and whether you use a $200 bino or a $1500 bino.
Phase coating for roof prism binos. Improves the contrast and clarity of the view. This is now available on all but the least expensive binos.
High-resolution coatings on all optical surfaces, including prisms. These are like multi-multi-coatings. Sometimes a hundred coatings. Allows much more light to be passed through the bino to your eye. Brighter images. Better apparent resolution. Better color detail in shadow. Another important development in mid-priced to the most expensive optics.
Silver-coated prisms. Another image brightening technology. Available in mid-price to top-end binos.
Di-electric coatings. Available in the best current optics. Allows the maximum amount of light to reach the eye.
In conclusion, the best new development in binocular manufacturing are coating technologies that dramatically improve the brightness of the image, which in turn has the biggest pay-off for image quality and enjoyment.
Lens construction technologies like FL-ED glass and aspherical elements seem more dubious to me in how much they actually improve the image, especially given their expense.
It is all in the eye of the beholder. Like buying expensive hi-fi, if you can tell the difference (and you can afford the premium) then go with it. If you can't tell the difference then save your money for other things.
And I do mean "If you can tell the difference". All the test bench results and reviews help but if you can't see the difference in hand, in the real world then why waste your money.