I have the regular size Bone creeper at work for use on less than perfect concrete floors. I found that small creeper wheels will catch on a pea sized stones or uneven cracks. The Bone's huge, high quality wheels are great on rough floors, cracks, small pebbles, etc.. That is it's best asset. It sits very low to the floor also, it's second best asset. The only con that I have noticed is that those corner "wheel towers" occasionally get in your way if you try to reach over the side of your head.
I would buy another one if mine ever got stolen (I don't think it will ever wear out).