It was my experience that when new firmware was loaded to my 5200 SL's it was absolutely necessary to toe in the speakers to achieve the expected EBA improvement forecasted. Without toe in the middle was missing.
I am happy now but still want to make an A to B check of 5200 Factory SE to 5200 upgraded i.e. without rings and new Alan Boothroyd feet.
Hector

AV: Thorens TD160B, SME, ShureV15MK2, 500, 598, 861v4, DSP7200.1, DSP3300HC Samsung UE55, SkyHD.
DINING: MS600, AC200, DSP5200SEUG.
STUDY 504, Roon Nucleus + RevB, 808v6, 5200SE, Mac & PC (Touch Screen), Prime+PS Grado GS1000i
HORIZONTAL: M80, MS200, Red Rose Spirit + Sonus Faber Toys, iPad Mini
A capella to Zydeco