My experience echos the OP's when I did the same upgrade. It was a noticeable improvement which even my significant other noticed despite me not telling here I made any changes.
That's my litmus test.
Comments on NODE 3 Power Supply Upgrade
I added a PD Creative power interface and a Teddy Pardo linear power supply to my NODE 3 N130. I’m not a critical listener and have high frequencies hearing loss. My memory of the “pre-upgrade” sound of my system is lost. Here’s what I think I hear after the upgrade:
1. More treble, so I turned it down 1.5db
2. Better vocals which stand out more, sound more real, more detail and decay
3. More bass, maybe I need to turn down subs to center of the dials
4. More decay overall for a more airy sound.
Im not sure if these are real or imagined. The difference is not a definite “wow”, but any improvement is acceptable. The sound is definitely not worse and sounds good to me. Any comments to help me evaluate this for future upgrades such as a DAC are appreciated.