The Gundry mod makes a vast difference in SH.
WOW! That is the most dramatic effect of SH that I've heard yet. The soundstage expanded beyond the walls.
As you, I rarely listen with SH engaged, and I found the effect marginal without the Gundry mod, but on a few recordings with the Gundry mod...
Dire Straits - Brothers In Arms
Doobie Brothers - What Were Once Vices...
Patricia Barber - Cafe Blue
Santana - Caravanserai, Abraxas
There was another that escapes me now that was very enjoyable.
I'll have to listen to some smooth jazz, country, and classical with SH engaged.