Most satisfying system change in 2017?

Finally dialing in my cartridge (vta/vtf/azimuth, Anti-skate, etc.)

switching out Soundsmith Zephyr MKII HOMI to a Lyra Delos MC

Added two SVS SB2000 subs, handing off to my monoblocks at 80 Hz and above (I can now run the volume on the preamp an eighth of a turn lower), the subs take care of everything below that, got them dialed in over a month’s time, had my audio buddies provide a critical ear, all is well!

"I see faces and traces of home...back in New York City"

Wow!

Got a lot of stuff this year, but streaming was the biggest change.  Tidal and Bluesound Vault 2 added the most--more than new amps, speakers, etc.

Three positive changes:

1. Clear Day Audio Double Shotgun speaker cables (2 pair)

2. Replacing PS Audio PPP with a P5.  An enormous improvement.

3. Replacing 24 year old Aragon 47k phono stage with Sutherland KC Vibe.

The only change in my system was to build a DIY Ultrasoinc RCM, cleaning every LP I own, and enjoying vinyl playback like never before. And, it only took $200 or so in parts, and works like a champ.

One of the best improvements in forty five years in audio.

Happy New Year,
Dan