Lets talk about filament spool placement for direct extruder printers. It is clear that with bowden extruder a spool can be put away next to the extruder. But what about direct drive ones? It seems that tried and tested method is right above the printhead. But recently I have seen more and more professional printers (yesterday ones from GermanRepRap) that have spools mounted at the bottom of the printers. There seems to be a long PTFE tubing between the spool and the extruder. Anyone can talk from the experience how well this work?