The change in bokeh is probably because the shape of the physical shutter contributes a little bit to the bokeh. Anyway, apart from the issues in shots with overexposed areas, I don't think the article's images look worse with electronic shutter vs. without, I guess it's a matter of preference. Also, electronic shutters can usually give you shorter exposure times than physical ones, which can be very useful when you are shooting in bright sunlight and still want to have the aperture fully open for depth-of-field effects.