Generally speaking, scopes faster than F6 won't give pinpoint star images very far out from the center sweet spot unless you use some very expensive glass.
I'm not sure why a visual observer would have F ratio fever? Consider that the field of view with an F8 scope and 30mm eyepiece will be the same as an F4 scope with a 15mm eyepiece. And the view through the F8 scopes will have less noticeable "seagulls" near the edge of the field.
Another thing to consider is exit pupil size. If you're a young fella you might get 7mm. As we age it's more like 5mm. If the ultra fast scope gives an exit pupil larger than our eye is capable of, the extra light is wasted.
To calculate exit pupil size, divide the aperture of the scope's objective lens by the magnification of the eyepiece. For instance if you have an 80mm objective say at F4 with a 40mm eyepiece, first work out focal length 80 x 4 = 320mm. Then work out magnification 320 / 40 = 8. Now that you have a magnification of 8, 80mm / 8 = 10mm exit pupil.
If you're middle age and have a 5mm max eye pupil size, that fast scope is just going to waste with any eyepiece over 20mm. You can still get wider views, but it won't be any brighter.
F ratio fever is for photographers.