Most satisfying system change in 2017?

Change from 20 yr Spectral owner to Pass Lab.

Added a Tru-lift tonearm lifter to TT. Makes playing vinyl almost as easy as CD. No adverse effect on SQ. 

Added a Schiit Audio Freya Tube Preamp and a Primaluna Prologue 5 Tube Amp.I use the all tube ckt for music and have even left it in the mix on some Movies after I had played some Dvd or Bluray concerts.Pretty sweet but,for Metal I go back to the SS Ckt.

+1 the single repeated most satisfying change: ROON

Knownothing.  
Use online calcs for cabinets and brace brace brace.  Also  all mdf. 1 in for front baffle of woofer cab.  All drivers have their own cabs and are isolated from one another w sorb Otha next, which improved detail tremendously.  
Ill get some images up ASAP. 

sorbithane