That is true of most zooms...imoBokeh is its weakness.
I've often thought that the lack of bokeh may be linked to it's seemingly deep DoF. It's not a people lens, but my best landscapes to date have been taken with that lens.
here's a quick snap of a guitar. No color correction or anything applied, straight out of the camera. 31mm, but cropped.
![]()
sg by stupidphotoguy, on flickr