Do I need higher quality power cords?

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

To clarify, I mean that if you have a stock cord running from the Orion to your amp (for example), use that cord from the wall to the Orion, and use the Elite PC from the Orion to your amp.