Pinnacle Souveran is generally regarded as one of the top pure caranauba pastes. However, it is about twice the price of P21S, and close to quadruple the price of P21S's counterpart, S100. The P21S/S100 is an incredible wax, and if you have never used it before, you will probably find it the best looking wax you have ever used.
If you are already a conniseur of fine waxes and are just looking for subtleties on a show car, you may be in the market to try Souveran. If not, I would recommend waiting for them to re-stock on P21S, or head to your local Harley shop for its S100 twin ($14.95).
Alternatively, stick with buying from Autopia and go with the Meguiars #16 paste. It has been a favorite, this season, with many members stating its looks are comparable to P21S and its durability is better!