Okay so I totally did this out of order — I did #6, the most challenging peak–The Flatirons at Superstition Mountains, as my third peak.  This was definitely a very challenging with a vertical climb of 3,147 feet requiring serious leg and arm work to get to the peak. Once you pass the bowl, it is very steep vertical climb the rest of the way up.  6.6 miles.  I have hiked the Grand Canyon 14 times from rim to river and back, and I would say the Flatirons is just a challenging and probably not something I would do again just due to the sheer steepness and danger in scaling the giant boulders to get to the top.  But aabsolutely stunning views from the top!!!