I think time as a type II plays into success the most.
I myself was diagnosed in november of 2010, went "kind of" primal through 2011 and did lose weight and control my blood sugar, but fasting sugars were still high. this year, i took the leap and revamped myself to 100% primal. Last month, my doctor told me I am no longer diabetic and removed it from my file. Oh, and I lost ~170lbs during all of this.
Another member here hasn't seen the same results though has been type II for longer. I'm sure he will chime in at some point. Just wanted to share my own experience.