Which motor should I use with my Shark Slider?

We offer:

1. direct drive motor (no gearbox) 
2. 14:1 geared motor (with planetary gear reduction)

In short:

1. motor (smaller drive pulley) in all situations where you are using the slider level. Never use this motor for angled or vertical shots.
2. Use the 14:1 geared motor (heavier motor with the round gearbox and larger drive pulley) anytime you are setting up angled shots on the slider.  Additionally, if you are shooting only timelapse - most users leave the 14:1 motor attached, even for level shots.  Your jog speed is lower, but if that's not an issue, then this might be easier to leave this on.