I finally replaced my Mark8 extruders with geared extruders. Major mod, had to drill new holes in top plate to fit 3 3d printed geared/belt extruders and then increase the height of the filament spool supports to clear the much bigger extruders. But...WHAT A DIFFERENCE! The extra torque is just whst this printer needs. Prints are much much better. The thing is, you cannot print fast with this thing no matter what you do so don’t try. With this geared extruder the recommended steps per mm of filament is around 800. But this high a value causes the geeetech to freak out! So, i set it to 200 steps per mm and then tell repetier to multiply the filament factor by 4, yes, 4. Totally not kosher but works. Also i print at 7mm/s. Yes, patience is a virtue. But prints are great!