I just stumbled onto this site the other day. PS3SACD.com is a guide to the models of PS3 that support SACD playback, their availability, catalog, and mods to improve the audio quality.
Interestingly, none of the mods are circuit based. They all have to do mechanical modifications, which will affect the resonance modes of the disc. This improves laser tracking, but what if skipping isn’t an issue? What sort of improvements will you hear? I raised this question a while back, while discussing BluSpec discs. It’s looking like I’ll need to dig into it a bit.