Royal Purple HPS (High Performance Street) - Experience?

[Icychap]

I've been using RP oil and filters for a while now with great results. But I've always used their "regular" API-licensed 5w30 stuff (Automotive - Royal Purple).

Then it hit me - I'm way out of warranty, what do I care? Shouldn't I switch to the HPS (Automotive - Royal Purple)?

So has anyone tried it? I'm referring specifically to the Royal Purple HPS (High Performance Street).

Thanks!