What exactly is slow in Stardraw Audio ?
If it is when drawing or dragging on a rack component in Rack Layout make sure that you do not have Snap To Intersection on. This is an extremely powerful but processor intensive function that can take a while to execute in a drawing that has a lot of objects in it, such as a Rack.
If it is something else, please reply to this post with an example of how to reproduce the slowness and we will fix the problem immediately.