Originally posted by Mr Hyde I'll try your suggestion tonight if it's clear and bump up the shutter speed a bit.
Assuming shake is not an issue, a faster shutter speed than 1/125 won't make an appreciable difference to the sharpness in the context of movement blur.
You might care to have a look at my calculations
in this post; at 1/125s, the movement is only a very small fraction of a pixel (about 1/25).
If lens performance is worse at the wider aperture you'll have to use, the result will be worse, all other things being equal.