I, for one, prefer the S setting.......
Yeah, I suspect it will be a personal preference/system dependent thing.
Like I said above I actually switched from the 'P' to the 'S' setting and pretty much forgot about it while I was concentrating on other aspects of my system.
When I switched back to the 'P' setting I was surprised how emphatically I preferred it - particularly on the Halcro/Harbeth speaker setup (Halcro amp was a new addition since comparing the settings).
In 'P' mode the presentation is more solid and 3D. Transients - whether guitar plucks, piano hammers, vocal or percussion - sound cleaner, more solid and focused. Vocalists and instruments sound more realistic and 'in the room'.
On the other hand the 'S' setting provides a bit more 'sheen/sparkle' - which can give more lustre and air to some material - but also has a tendency to sound a bit bright and sibilant on (some) vocals. It just doesn't sound as engaging, solid or realistic to me.
Clearly this is a case of YMMV, but its worth playing around with to see what individuals prefer.