Regarding that latter merit, here's Darren Willman, proprietor of the most excellent Baseball Savant ...
If the season ended today, Aroldis Chapman would be the 1st pitcher in PITCHfx era to average 100MPH+ on his fastball http://t.co/aPXOH7kexi— Daren Willman (@darenw) August 30, 2014
Here's the list of contenders for highest average fastball in the Pitchfx era (i.e., since 2006 or so). In matters related, the slowest fastball Chapman has uncorked this season checked in at 95 mph. So, yes, he's hasty on an unprecedented scale.
It's no coincidence that Chapman this season has struck out an astounding 51.8 percent of batters faced. It's also no coincidence that he's one of the best closers in baseball.