Dave Smith Instruments uses a unique type of glide or portamento. In some ways, it's hard to understand it and be able to predict exactly how and when it will affect a moment of music. This is true, no matter what Glide option is used. It doesn't give you that smooth harmonious sweep from a low point to an upper chord, or vice versa. The old Rolands were good for that effect. Instead, the DSI glide is a much more complicated effect that gets entwined among the individual notes of a chord. The chord doesn't move as a whole, but each note is affected differently. It sounds more natural and less synthetic, almost like the subtle gliding that can be achieved on a string instrument; but again, it's more complicated as well. I consider it a nuance, rather than a function. I find that, if I'm going to use it in a piece of music, I have to rehearse it several times first and get familiar with it's character. You can control it in a general way, but yet not entirely. This improvisation is an example:
https://www.youtube.com/watch?v=OYWO2bX9C20