Thank youI have one of both, the older ribbed and the newer pebble top. I don't really notice any difference in doing
step workouts, but when using the step as a "weight" bench, the pebble top is so much more comfortable
to lay on, put your hands, knees on, etc than the ribbed top. Of course, you can always use a mat on
top, but I tend not to do that or forget to grab the mat, so it's easier with the smoother type top IMO.