I've got a pair of the stock Lexan/ABS? rudders that came with my 1997 H21sc and frankly they have seen better days. My preference would be to replace them with some of the older black EPO rudders which I have never had problems on H16s however they seem to be pretty pricey. A local Hobie dealer has a pair that they rebuilt for $470. Assuming they were rebuilt/ painted properly it's probably a fair price as a used set is hard to come by.
The entry level (plastic) rudders from Hobie would be roughly $320 for a set and brand spanking new.
Any Hobie sailors out there that can comment on the value of getting a used set of EPOs vs. the new plastic rudders?