this is a very good point. im using leica MATE (F4) on my XE1 and A6000. the EVF is close to useless when stopped down to F8 and try to get a sunset shot. or try to do a indoor shot in a not-so-bright placePersonally I just like fast glass. Viewing for one, bokeh is nicer and most times a lens performs better 2 stops down from the widest aperture a f4 becomes a good F 8 but a good 1.4 becomes a good 2.8. That plus if your trying to get maximum IQ not matter what lower ISO will provide that. But if want smaller lighter lenses than the slower lenses are it. Here is the issue we need the choices to start with. I'm cocktail induced. Lol
Just got to the beach and had a few libations. Man I needed that. Lol
(remember unlike electronically controlled aperatures, which remains in max aperature until just before shutter is release, these mechnical lens close aperature before the shutter is even pressed.)