I set my speed around 4. I clicked on underclock. Overclock speeds it up more but from what I've read on the info it will decrease the life of your phone. They say that Apple underclocks the phone so it can last longer. Correct me if I'm wrong.
I would install springtomize and go into animations and lower the speed down to around 1 or 2. It does the same thing as speed intensifier. It uninstalled itself once I downloaded springtomized. I get more options with springtomized than SI.