Do I need higher quality power cords?

@rvpiano ime the power cord from the wall to the conditioner is actually the least important PC in any system -- provided you get a good base level top let the conditioner do its job then you will get more impact from the PCs to the components. This assumes a conditioner that is not current limiting

The Elite cord itself is to my mind problematic as per IsoTek's own description it is not suitable for high current usage -- a PC to a power conditioner should be for the highest current rating possible (unless you only use the conditioner with sources)

Elite can be used with small to medium power amplifiers to great effect but for very large power amplifiers EVO3 Optimum proves the better choice.

In terms of where best to try a PC upgrade I'd start with the turntable (in my experience turntables are very sensitive to PC quality -- a step up from v2 to v3 Marigo Iridium in my system brought appreciably improved tactility and stability to my EAR DiscMaster), and the CD Transport

The latest AQ PCs are good value for the performance and worth trying but price/performance also depends on the country you are in

Definitely see about getting "loaners" to try in your system (Cable Co. is a good place for this), as it is clear that different people with different gear find markedly different results.  My personal experience is that the power cord is the most important cabling for system sonic performance, and that has remained consistent for many years over a lot of different gear.  I happen to be a huge fan of Elrod cords.

I have found that putting my best power cord feeding my power conditioner made the biggest difference (Shunyata Hydra 8, Audience aR6, Audiodharma Power Wing, Weizhi PR-6, HB Cable Design Acrylic & Marble - - all benefited from being fed by the best cord).  I am now using a PS Audio P10 power regenerator, and while it is not insensitive to the cord feeding it (the stock cord is bested by aftermarket cords), using top of the line Elrod cords did not make any difference vs. an older Statement cord, so I have stuck with that.  But, even though the P10 delivers very pure and correct power to my gear, you would not miss the improvements wrought by using better power cords between it and the components it feeds.  My 2 cents.

I have a Torus for my gear. I use stock unshielded power cables. I've tried using stock shielded cables and I didn't like them. I did later find out that the drain wire was connected on both sides. That makes sense.

I've read people recommending shielded power cords that have either their shield attached only to the component to prevent interference generated by the component from coming out. On the other hand, I've also seen recommendation of shield attached only to the plug at the wall end to prevent the noise going into the component.

How do you decide which one is suitable for a given gear? Are there other problems with these two designs that I'm not aware of?

Again, this is within the context that I have a Torus and I keep my power cables away from my well shielded and twisted balanced signal cables. I've tried putting nasty stuff near my interconnects and couldn't make them sound worse.

Anyone wants to help me understand?

If you like the Isotek, and I'm guessing you do, why not more of their cords?  And buying used is a great way to go tons of used power cords on here all the time.

Alright - clearly I'm a little biased, but here goes:
First, ensure that you can separate "high quality/caliber" from "expensive" - they are not one and the same. ;)
Second, no matter how much care you take in the selection and/or use of dedicated outlets, line conditioner(s), voltage regulators, or anything related to power (the "power chain"), it's all for nothing without a quality PC to your gear (the last link in the chain).
Speaking of the "power chain", for those of you who argue that you are limited by said chain, so nothing you do at the end of it matters, I'll say this - while you may not be able to strengthen a chain by adding a link at the end, you can certainly weaken it.
To put it another way, good tires will not get you more horsepower, but lower quality tires will transfer less power to the road.
I agree with the poster who said the PC to your conditioner is the least important, so here's a simple experiment (forgive me if this has already been mentioned) - swap the Elite PC with one of your stock cords and see what's what.
Cheers and good luck!

Nawaz
nrgcustomcables.ca