I do not agree that high end DSLR glass is sharpest around F5,6 -F8 these days (thats an old 35mm film rumour). Most tests indicate about 1-2 stops over widest aperture.
Most of my high end DSLR glass is sharpest around 2,8-F4 but I do own a lot of f1,4 glass.
Since you more or less always...