I had an i-motion 9 for about a week.
It was noisy and had noticeable drag and I didn't care for the huge honkin shifter. Plus I now had to carry extra tools since there was no quick release for the wheel.
Everything about my regular 9 speed cassette and friction bar-end shifters was so much easier, simpler and better for me.
But I don't have snow or hills to worry about. So there was no benefit at all.

The good thing about the i-9 was the quick release shift cable if you do have to remove the wheel. That was nifty. My dad's nexus on his Electra Townie is a SUPER PITA!