SRAM X01 Grip / Twister Shifter

Living in the uppy-downy switchback thick terrain of Prescott I do a lot of rear cassette shifting.  But not so much FD shifting.  As much as I like the SRAM TT900 lever it has become both a small danger and annoyance. 
 
Shifting to a lower gear means that I have to pull on the lever, having a slightly destabilizing effect on the steering.  As well, pulling on the lever requires me to move my right hand off the handlebar, position the lever in the palm of my hand, push/pull up on the lever and then replace my grip on the handlebar.  That may sound like a minor step but when you're navigating switchbacks, up and down, it can be ... slightly dangerous and certainly annoying.
 
Hence my recent replacement of the SRAM TT900 right lever with the SRAM X01 Grip Shifter.  A mountain bike shifter.  Properly installed it allows for quick, one motion, shifting.  And to my surprise it is incredibly light. 
 
- d
 
https://www.sram.com/sram/mountain/products/sram-x0-grip-shift