a lower center of gravity makes it fall over slower (precess slower), and taking the cap off lowers the center of gravity, i suppose it might be personal preference... if you are popping to a sideways regen (drumbeat or sewing machine or joker choker) it may not be as important... my qs is an original, not a hybrid, so the cap was aluminum too, so the weight of the cap was a lot more significant, your experience may be very much different if you leave the plastic cap on...