I'm using the same method and it's taking me just about as long as you to finish that section. I honestly wouldn't worry too much about what Kaplan recommends as they're not you nor do they know anything about your strengths and/or weaknesses. Personally, I've found though that I fly through angles, cube counting, and pattern folding with very good results, so I allow myself a little longer for the tougher keyholes, TFEs, and hole punching problems.