The KH Moment have a 10mm Q factor and the Spirit have a 12mm Q factor.
The zero Q factor cranks give a feeling to pedal “straighter” because as too are closer to the wheel, you wooble slightly less while pedaling.
However, on a KH29 with 100mm cranks (or even with 125mm in steep downhill roads), it forces a bit on the knees and I had a couple of time a pain sensation in one knee for a couple of days after a ride.
YMMV but it is good to be careful. If you have other uni riders not too far away, the best is to try and swap cranks to see how it feels (however my knee example too a while before being noticeable).