Answer: The "Glide" switch is a full MIDI continuous controller (cc#5 - Portamento) according to Nyle Steiner. He claims that the more of the portamento plate you cover with your thumb, the more portamento you get, but I've never found that to be the case. The front panel of the modules have an adjustment knob for the glide parameter and there are certain programming features for it as well. While you can program external synths to add a sound depending on whether you are touching the glide sensor for example, you're not going to get a wide range of continuous control like you would from a pedal hooked up to cc#5.