Advice needed: Have 2 Power Cables only need 1 - Which is better?

First world problem. Don't waste your time agonizing over insignificant details. You said both sound good. Pick the prettier or cheaper one and sell the other. Spend more time enjoying the music.

How can someone who’s not heard your system or has no idea what you like can tell you which one of the two cables is better. The only person who would know that is you.

And if you ask my opinion I would sell both and buy a kimber pk ascent. 

@audphile1 - Totally agree.  I think my point which I could have stated better is that I'm "happy" with either but trying to determine if others have experience with both to make a "tie breaker" call.   I think the Mongoose has a bit more ease/liquidity, but with some small sacrifice of detail from the Cardas Golden.  Love them both and both better sadly than the newer Cardas cables at least to my DAC.

Keep both you'll need plenty more in the future 

There's no objective difference with cords and cables, especially power cords, so sell the one to another sucker that will bring in the most $$$.