I'd buy the Gigabyte.
Why? Because I had a bad experience with Asus.
Which is a poor although understandable reason......that you should ignore.
Suppose you choose brand X and it turns out bad for you. There's only a small chance that "VRM" will be the direct source of your unhappiness and even less chance that choosing the other brand would have necessarily given you a better experience.
And even less chance that if you only had done another 100 hours of hand-wringing and "research" that you would have improved the chances of being satisfied.
But in all honesty, who can overlook the fact that 12 is a larger number than (10 plus 1)?
I'm asking because it's 6+6 parallel design. Even on Gigabyte's website itself:
https://au.aorus.com/blog-detail.php?i=974
Typical Power Design on Motherboard
Parallel is a common power design that could be found on motherboards. As per Figure 1 below, although it looks like a two-phased power, it could be regarded as a single-phase power because both its circuits are controlled by one PWM. The equivalent resistance could get lower with this kind of power design, but it also gets hotter, which is due to the poor loads to the current. If you pair a higher-end processor with the motherboard with a parallel power design, you may not get the full performance of the processor.
As opposed to direct power, which seems to be the 10 that Asus use? -
The Direct power design allows PWM to communicate with multiple Dr. MOS simultaneously and comes up with multiple independent circuits. Direct is the most premium power design of motherboards right now because it features the lowest temperature & the best capability with respect to current loads. This means that this power design could perfectly match the most premium processors in the market, and you could do something more extreme with your processor and motherboards like overclocking or a long-period of heavy loads.