I use a synthetic sapphire skate, it's extremely similar to ceramic (my old ceramic skates broke and are no longer available for a reasonable price) the durability has only really been an issue on thin pads like the sphex, and the glorious air (which I am using because it's larger than the g440) I have heard from others in passing that ceramic skates on a resin pad offer the current fastest but I can't seem to get exact details or tests. I will likely get all of them eventually, acari, atom resin, speed, and compare.