Different plugs can change the sound of a given power cord quite significantly. I ditched the stock cheapo Wattgates on power cords from Sunny Cables (P600) and Cerious Technology in favor of Oyaide 046 male plugs and IeGO 8085 female plugs (gold plated). Both cords opened up quite a bit with greater detail, better focus, and a wider, deeper soundstage. The top end also had more air. After hearing the improvements with the better plugs, I couldn't possibly go back to the stock plugs.
Currently, I don't use manufactured power cords. I've made my own using wire from Mundorf and some heavy gauge solid core silver plated copper. I still like the Oyaide 046 plugs but find the IeGO 8095 to be tops for detail while taking the edge off. This is a fantastic plug. You can find the IeGO stuff at acoustic-fun(dot)com and I highly recommend the 8095 (rhodium over solid silver). Their 8075 (rhodium over copper) is also very good but looses a bit of detail compared to the 8095 but is about half the price. I no longer use their gold plated plugs (or any gold plated plugs) as they loose top end air and bottom octave detail compared to the other plugs mentioned.
All in all, if you find a power cord you like but find something lacking, you can take its performance up a notch or two by upgrading plugs though you might very well change its entire sonic character by changing the plugs as well. My advice is to purchase a few plugs and experiment. Its kinda horrifying to chop up an expensive power cord but the likely improvements are well worth it in my experience. Good luck!
