It think it is more important to have consistent hydrometer readings than it is to have precise readings. After all you want repeatability. Precise readings are nice to have if you want to exchange that data with other home brewers.
I agree. Precise (consistant) readings are good for repeatability. Precision allows one to track changes despite inaccuracy. However, accuracy is needed to exchange meaningful data with other homebrewers.
As a system operator I sometimes have to track process trends using precise online monitors, whose accuracy is out of calibration.