Honestly, even if they replace it, it will only be marginally better. http://www.soliforum.com/post/31960/#p31960
They acknowledge that there are several issues causing banding. I think you best bet is to pick a fix from the forums and run with it. I have had wonderful success with my slop nut design using M5 threaded rod. I am sure M3 works well also.
SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.