When and what was your last significant equipment upgrade?

Sold my PS Audio P5 Power Plant earlier this year only to yearn for another.  Recently replaced it with a P10.  Suprisingly it's a solid upgrade even on light duty sources only. 

replaced MIT MI-330 pre-to-amp interconnect and MH 750 Tube Terminators speaker cables ( both of which I gave to Goodwill - the costs to reterminate the bad connectors plus time, effort and cost to list and sell, was close to their value as old used cables; not worth the time and trouble) with Grover Huffman cables.  A tremendous upgrade in clarity.

@gshepardbuster  Can you elaborate on the differences between the P5 and P10?  I am on my second PS unit.  I went from a P500 to a Premier.  

@hifiman5  The P10 has a more relaxed feel, it's more detailed but nuanced not analytical.  Decays are better.  It feels as if I'm in a bigger hall, the ambiance is improved.  

Almost forgot, plug into the high current outlets if possible.