As you may be able to tell from my other thread, I'm designing a printer. And a big thing I'm trying to decide on is the extruder (that and build area but that's easier to customize later).

The obvious question is bowden vs direct, and my answer is I'll design it so it can use both interchangeably. What I really want opinions on are geared vs direct, and single sided (with idler) vs double sided drive (two driven hobbed gears grip filament from both sides).

I only really have experiences with a direct drive mk 8 type extruder, so other people's experiences and opinions are very much welcome. I understand that gearing the motor gives you more torque and more resolution, but what is that torque good for (able to force more filament through the extruder so faster print speeds than non geared? Or do printers never go so fast as that this becomes a problem), and is the extra resolution necessary?

Secondly, with double sided drives like the bondtech, this means you have more grip on the filament and are less likely to slip and grind the filament, but again, is this really an issue? I also imagine you'd have more precise control than with an idler and can do faster retractions and extrusions as the hobbed gears or bolts are less likely to slip when there's two of them.

Thanks in advance for any ideas, opinions or suggestions!