To power condition or not to power condition AVR

99.9% of AVRs have the very cheapest quality build power supplies made-in-Chin that simply don't compete with any quality build audio amp.  they are built to a very very low price-point and resulting build quality point.  Add to this the crap build quality quotient because it is Chi-fi.......

accordingly,

(1)  high end power cords are not going to provide you with any added video or audio step up in performance..... resist the illusion that high end power cords are any silver bullet. There are a buzzilion PCs up to a $150 pricepoint that handily best the POS quality stock power cords but max out performance wise in video.
(2) contemporaneously, with the absence of a quality build power supply,  the introduction of a power conditioner won't provide you with any further improvement past (1)

what will I'll add the best improvement for AVR and display units:

--run a dedicated power line line from the breaker box to proper hospital grade (or better) wall receptacles and just plug it in directly.

Unless you have wild power swings because you live in an old apartment or the like, where a power conditioner assists in flattening out the swings with an element of surge protection, there is no reason to introduce a power conditioner.

as properly highlighted in the prior posts, they are just detracting and limiting filters that detract from audio performance. 

As AVRs already suffer from lousy cheap power supplies, the filtering effects are magnified to the negative, not the positive.