Play a record of acoustic bass by, say, Charlie Haden's "Closeness" with Alice Coltrane and you will hear the delicacy of his plucking and tunefulness and its deep richness.
Couldn't agree more with your assessment of bass performance with SP10MK2 and MK3 and remarkable you mention one of my all time reference LPs. I don't think another post at Audiogon ever mentioned "Closeness."
If you don't already have it, the other Charlie Haden that has the same effect on me is "The Golden Number," Duets with Don Cherry Ornette Coleman, Hampton Hawes and Archie Shep. Truly great stuff, Horizon 26 by A&M.