Power Cord brands mixing. "Your Opinions"

You match a power cord and the component, generally speaking. In some cases there might be synergy if using the same brand especially if all your components are the same brand too.
Anyway, if I could put something like Purist Limited on every component I have, I would certainly try that first and then compare the result with some other cords somewhere in the system.
And another thought. If the cord is really good, it will work at least well if not always great with any piece of equipment.

Actually, I have Custom Power Cord Co. Top Gun cords on all three components - Redgum RGi120 integrated, Acoustech phono stage and CEC belt drive player. My Nottingham and Nak deck have fixed cords. I would probably experiment later with some Purist and maybe other brands though I don't really feel the need to do it.

Mrtennis, could you please list your entire system?
" If it sounds good it is good ". That may be but it doesn't mean that it can't be improved. We are not only talking about big difference but also about fine-tuning, if I got it right.
In any case, stable and clean current from the wall or battery is far more important than all the power cords in the world. When the current is really bad, my stereo sounds like a good very expensive boombox, and when it is good - well, it sounds very good.

Your system may not have enough resolution to hear subtle differences so the results of your experiments with power cords, all same brand or mixture would probably be inconclusive. I may be wrong but that's how it seems.