i hv done quite a number of power cord shootouts in my system (in the last 6 mths). these include - Acrolink Mexcel 7N 9100, DCCA, Elrod Sig.2, Harmonix Studio Master, Jena Labs Model 1, Jorma Super Power, Kondo KSL-ACz, Nordost Valhalla, Pranawire Samadhi, Pranawire Satori, Purist Audio Dominus (fluid & ferox), Shunyata Anaconda Helix (alpha & VX), Stealth Dream (source, power amp & preamp versions).
here are a few observations & suggestions:
a) there are no 'best' cables/cords.
a popular &/or more expansive cable does not necessarily mean it's going to be
better in your system. component-cable synergy is key;
b) some components are more sensitive to power cords changes than others.
if you're looking to replace power cords in a number of components, try to focus
on the component(s) that are most sensitive;
c) many cable brands make a range of cables & many of these cables will share the
same characteristics (but get better as you move up the line), start will lower priced
cables if you hv a limited budget. move up that particular manufacturer's line once
you've identified a cable/cord brand that's most synergistic;
d) i generally prefer to match a power cord to each component (vs. inserting a cord,
then assessing its impact on the overall system alone). although this is considerably
more tedious (& requires surplus components, cables, etc.), once a match has been
made, i can effectively take the cord-component pairing out of the equation (i.e. i'll
know the cord is not just patching up an up/downstream deficiency). furthermore,
any new cords introduced to the system will only need to beat the last favorite;
the general characteristics you should look out for (when trying new cords) include tonal balance, dynamic range, musical coherence (across the audio spectrum), resolution, pace, size/solidity & presentation of soundstage, etc. these are all highly subjective, so unless you know you hv a similar system & share similar preferences as someone else, don't waste your time reading how a particular cable (in someone else's system) brought tears to their eyes. you'll just be wasting yr time.
finally, hv fun...