It is possible to replace pstopdf with pstocairo (and return to the default) with these commands:
$ lpadmin -p <printer> -o pdftops-renderer-default=pdftocairo
to switch over and
$ lpadmin -p <printer> -R pdftops-renderer-default=pstopdf
to switch back.
In my case (HP Color Laserjet 2605), it is much better.
See Bug #1476705 for a similar issue.
It is possible to replace pstopdf with pstocairo (and return to the default) with these commands:
$ lpadmin -p <printer> -o pdftops- renderer- default= pdftocairo renderer- default= pstopdf
to switch over and
$ lpadmin -p <printer> -R pdftops-
to switch back.
In my case (HP Color Laserjet 2605), it is much better.