Mercedes SP Build.

I have used Gust Dive a total of 2 times 70-190.

I used Gust Dive a pomegranate ton 70-140. On the completely flat maps with no platforms that I could land on, the increased mobility on the maps made it so I could clear entire spawn before they all respawned, then the Red Dragon Turtle map is just amazingly fun when you combine Gust Dive > Rising Rush > Moonsault. You can circle the map in a matter of seconds.

Its only drawback, is that you won't be able to push all mobs back with Rising Rush after using Gust Dive. Though that isn't much of an issue with max Final Attack and Elemental Knights, and a decent range. That way you won't be leaving any mobs behind because you'll kill them. It all depends on where you train, really.