Best sounding 7189 in my pilot 232 is by far RCA (1960/1961)
I own perfectly matched quads of Sylvania 7189 and Holland 1959 "D" getter 7189 among others of lesser note. Along with the RCA 7189, I am using Mullard fat base as GZ34, Tungsol 5751 as 12ax7 and suprisingly, a 1954 Holland pinched waist e80cc as splitter...I find the e80cc
extends both top and bottom and sharpens imaging over any other 12au7 variant when used as splitter (big difference)and increases dynamics.
My system is all tube and inserting a few e80cc tubes in stratregic locations provides tube warmth with solid state extension and tightness.