Maximum F/stops are always about size, weight, and price. If you want faster, it's there but you pay more for it and have larger, heavier gear in return.4800 Dollars for 6.3 aperture?
Not that much faster than my 500mm PF and sharpness about the same.
Thanks Nikon but i will keep my 500mm PF.
F6.3 isn't much different to F5.6.
F7.1 isn't much different than 6.3.
If you're already at F7.1, F8 isn't a big deal.
Before you know it you're at F11 wondering if you've accidentally mounted a Canon lens.
If this had been an F/7.1 lens, I would have been much harder on it and at F/8 it would have been a joke. Everyone has their cutoff. F/6.3 has really become de facto F/stop any 600mm for any affordable / compact piece of gear, so I don't think the slop is quite a slippery as your example would suggest