I've narrowed my power cord choices for the 501s down to the Wireworld Aurora 52, Stratus 52, PS Audio Jewel AC, AC-3 (outside shot), Pangea AC-14 (for sources only, though they can be used with power amps), and Shunyata Venom3. These all reflect the state of my budget at this point, and the AC-3 is the most expensive of the bunch (MSRP $239.99/2m).
I haven't determined how I want to set up finally. Now, I'm using a power strip to extend the right 501 to my LCR2400 power conditioner; I think an extension cord would be better but the best is a direct connection, which means a 3m cord (and more money). I am also considering a PSA Duet to extend my LCR to the wall rather than plug in directly, to offer an additional layer of filtering and the automatic shut-down feature; this is available with my current setup, but the HT1210 the LCR goes into has a 14-gauge cord rather than a 12-gauge as the LCR has. I wonder if I'm limiting current, even though the system doesn't pull anything near the HT1210's capacity (12A, whereas when playing music the system pulls only around 2A). Getting a Duet would necessitate another cable.
I notice a lot of people with WW cords on their Macs, some with PSA cords. Venom is getting a lot of positive press, but the 1.5m length is tricky in case I reconfigure my system and they prove too short. I was thinking about doing that next year if possible, with a Salamander rack replacing the Hooker cabinet I use now. The PSA cords have the detachable ground pin, which could be an advantage; they and the Pangeas also come in a C7 configuration should I go for upgrading my source components that use them.
Then, of course, there's flexibility. This is a major criterion, and the PSA AC-3 would be the least flexible from what I gather so far. The new WWs are said to be flexible, and due to multi-strand construction I'd think the Jewel AC is also. The Venom3 extension cord I have isn't too bad.
I have a $500 credit with The Cable Company I want to use. I'm hoping to sort this out soon.