Summary:
I have gone through many power cords, from the NBS Pro to the Synergistics to the Electraglides to the ESP Essence. When it comes to bringing a line-level component to its performance potential, the new Tek Line power cord came out on top. Available with various finishes and connectors, I do say it is worth it to get the top-of-the-line Watt-A-Gate connectors. Using the Tek Line Watt-A-Gate, the background is "more silent" and one can hear into the low-level information and cues better than any other cord. The Hubbell model is also excellent.
What makes these power cords special? The Tek Line power cords simply impart less of a sonic signature with the components used, and consistently so. You hear the recording and component, with very little alteration from the power cord itself. And with better components, one feels closer to the original venue when the Tek Line power cords are feeding power to those components.

Best of all, the prices of the Tek Line power cords will not force you to get a second mortgage in order to own them. And Tek Line owner Scott Richardson has **the** most liberal auditioning policy in the business. Bravo. Five speakers.

Summary:
Before I did this comparison I wasn't expecting much differences between power cords (they only have better shielding right?). But in the end, I have to admit that the differences are quite huge. It's even more apparent than changing speaker cables. Heck, if my 16 year old brother can accurately tell the differences there must be something going on here. Ok, here it goes:
Associated components:

Krell KAV300i & Meridian 551 integrated amps
Totem 1 (basic)
Camelot Arthur 3.0 DAC
AA DTIPro 32
Parasound changer
Transparent Audio interconnects + speaker cables


Power Cords:

Tek Line PC-4
Tek Line Quat-PC
Tara Labs Prism AC
Tara Labs Quantum AC
MAS Master Power AC
LAT Int. AC-2

All powercords were used in conjunction with the amps. The other components used their own original cords.


Results:

Both Tara cords sounded similar but Prism AC had fuller body and blacker background. As compared to the other cables, they sounded dull without any strong characteristic. The LAT cord was the brightest of the bunch. It was the most forward sounding and transparent. Very crisp treble and the midrange sounded smooth but lacked definition and fullness. I found it to be the best performer for hardcore rock music. The MAS was the darkest sounding of all. Compared to Tek Line's Quat-PC (similarly priced), it was not as musical and full bodied. When used with the Krell, the midrange sounded muffled. The Tek Line PC-4 is the most balanced performer. Midrange sounded smooth but full bodied, something that the LAT lacked. Treble was not as crisp as the LAT but sweeter than the other contenders. Bass didn't sound as tight and deep as the Quat-PC but matched well with the rest of the sound.
The purpose of this summary is not to prove which power cord is the best. It is merely a guide for those who are trying to match a cord with his system. Tek Line PC-4 works best for my system but different people have different taste. I have not tried them on digital components but I'm currently using the MAS and Tara Prism with the transport and DAC. If anyone has done a comparison of power cords on digital components, I am certainly interested in reading the results. It would be interesting to know the effects of bright or dark sounding cords on digital signal.