After all my yapping, maybe I had better sum up my thoughts on the Stainless Steel bearing:
1, It can only take 80-85% of an equivalent steel bearing load
2, The RS seal is good only at 35% less speed than a Z seal (20,000 less 35% = 13,000 rpm) 2RS means it has two seals, one on each side.
3, The cage the ***** run in also has to be correct for the highest speeds

These limitations make it worse than the stock seal fitted with Z or V seals.