I've been doing it wrong for so long, and it's been working for me... D:
Damn real world application versus hypothetical and controlled testing!
So an f1.4 lens being shot at f2ish may have a better quality/sharpness as a result of being stopped down a little, PLUS picture overall BETTER lighting!?
This is actually a good point. But it would depend on your camera. Some did better then others. Plus the wider primes usually have nicer glass. So you would still benefit from that even if you lose a bit of light.
I would like to see someone do a really comprehensive test on this subject where you see full brand line ups and see how the lenses stack up on each.