Speed up Mission Control Preview Animation
Not sure why you're using ctrl-shift to do this. This exits Mission Control, but selects the desktop you clicked on. The reason the animation is so slow is that you're held shift (which slows down many OS X animations). Holding ctrl does nothing.

I think what you want to do is switch the preview area of Mission Control to show the contents of another desktop.
This is accomplished by option clicking on the Desktop you want to preview.