>>4159968Bokeh should be the last reason to buy a fast lens.
Sharpness is good and optical defects are not (usually), so you have to stop down your lens. If you want a shallow depth of field you can move away from your subject. Then you have to use a longer focal lenght to have the same frame. This have the added benefit of a tighter perspetive.
Lot's of people don't realize they just want a longer lens, not a fastest one.
