Sliders in my experience "act" 1 gr lighter. Get 6.5's if you wanted 5.5 rollers
..yeah, this is true of Dr Pulley sliders...
..ninja sliders, not so much..
..i had previously praised the ninjas, because they worked differently (better?) than rollers in my scoots..
..i've come to realize now, that the dr pulley sliders perform 10 times better than the (same weight) ninjas..
..i will chronicle this in my "sister-sister" thread later today...