Older Power Cables

There have been some big improvements in power cords in the last couple decades and a lot in the last few years. Find a way to borrow an Audio Quest Storm series power cord. Then you can move it from component to component to get a feel for the difference you will get. Start with the a,p. It is likely the difference will be striking.

There have been great advances in the element Cu.

@ghdprentice 

+1

@joscow 

Try to audition an AQ Hurricane. The sweet spot in their line-up. 

Think this will depend on your system also. There have been advances in technology for sure, the question is can your system maximize these upgrades. It could be like putting Pirelli T-Zeros on a 1978 F-150.   

what will differences will I likely  be able to "hear" by replacing them with some of the newer power cords that is currently being market

NOTHING.

There are plenty of beautiful 10awg power cables you can buy on amazon/ebay for less than $50. Will definitely please your eyes and perform like $1000 cables or even better.

"WAudio 3.3FT AC Power Cable 10AWG HiFi Audiophile Power Cord with US Plug IEC Connector" 

I'm not affiliated with the manufacturer/seller/online-platform.

You're going to have to try some new cables to find out.

I like SR's stuff, but have had good results with the higher-end GR power cables, too. (The GR cable took FOREVER to break in, so bear that in mind...).

@joscow - As mentioned above there have been significant improvements

1. metalurgy - e.g. UP-OCC copper - that improve details and dynamics
2. Insulations - low dielectric constant insulations that improve clarity
3. Cable Geometry - lowers noise floor and improves clarity and image

Take a look at Audio Envy or Zavfino - both reat cables

Regards - Steve