I am using Jena Labs "Pathfinder" aka the 7 strand powercord, speed and air seem to be there strength's. They don't do anything wrong in my system so I think its a great combo for me. However like Saxman2 said power cords are VERY system dependent and personal preference is the other big factor. I don't think you can go wrong with Elrod, Shunyata, Jena Labs, Silent Source or Harmonix- just depends what you want from a cord at this level.
I am going to experiment with some "cheaper" power cords on the transport and see what happens. There is no ground pin on the unit and as I understand it, a lot of the magic of power cords has to due with the ground. Has anyone else tried this?