Most satisfying system change in 2017?

In all honesty EVERYTHING was a big deal this year.
Lets see
Discovered streaming and Tidal via Bluesound Vault 2...check
Replaced my McIntosh preamp with Exogal Comet Plus DAC/Pre..check
Replaced my old Focal speakers with Wilson Witt series1...check
Replaced all interconnects with Nordost ones, speaker cables with Analysis Plus Oval 9....check
Replaced fuses with SR Black....check
Replaced my Clearaudio tt with one I have lusted over for years, a Nottingham Analogue Spacedeck cw Shelter 501 mk3 cart

Just hard to pick a winner here!
Time to sit back and enjoy the music

Additions...
Multibit upgrade to Schiit Gungnir
Schiit Freya
First Watt F7- now music from the Silverline Prelude Pluses finally sounds wonderful

Upgrading from unshielded Volex power cables to unshielded Signal Cable MagicPower cables on all my sources, phono preamp and main preamp.

Mastersound monoblocks PF100. Biggest upgrade ever on my system.

@uberwaltz Was the Exogal fuse swap difficult ? What size and spec would other comet users need ? Thanks,mike.