Just read an interesting review on the Roller-Skid.  The new customer was very happy with the Roller-Skid after replacing the Solid Polymer Ariens Skid that he had on his machine prior.  The fact is, the plastic skids still wear down (possibly faster than the steel skids?)... which results in the height of the scraper bar dropping down! This now results in the scraper bar doing just what you don't want it to do on your nice driveway and walkway surfaces: SCRAPING!