What are the differences between Tein's lower line (SS) vs the what somehere has called them "the big boy suspension" (RA, RE, RS)? When it comes to the top of the line, I think that if you are going to spend the money, for good suspension, you might as well go all the way with the RS because it is double adjustable. How about the RA/RE vs SS? Is the price difference due to the material used(metal vs aluminum)? Is the piston size different? Because RA/RE are valved for higher spring rates, is this a factor in price?

Anyone who has have experience or have looked into it, I would appreciate some insight.