The organ pipe hotend extrudes ABS.
The calibration still has to be done ...
... but I am impressed by the quality.
Up to now I only used Skeinforge, but this is the first time I used Slic3r.
In the past I had difficulties to extrude this spool of ABS at all. I seriously thought about throwing it away. But the organ pipe hotend does its job very well.
Even the leaking of ABS at the soldering areas has gone.
No ABS leaks out.