New power cords for Vintage amps

I have a McIntosh 2105 (solid state) that had the original captive skinny lamp cord type power cord. I had an authorized Mac tech put in an IEC, and then I attached a Pangea AC9 SE cord.
The amp gained authority in the bass region, and also seemed more quiet, although that never seemed to be a problem. I think that it is worthwhile.

I removed the captured power cord from a vintage Harman Kardon amp and installed an IEC socket. I also removed the original 18 gauge cable that ran from the throughout the amp up to the power transformer and replaced it with 14 gauge wire. It was a fun project, but I won't say I heard a difference.
If you can do it yourself, I say go for it. If you're going to pay a couple hundred dollars...that's a different question.

These amps have the original captive power cords and they're approaching 60 years. Not crazy about playing with electricity.