I use a pedalboard as a part of my street performance and I now use 12 pedals, mostly micro-sized, on a 38 * 30 cm pedalboard. Making the best of every millimeter of space is a high priority for me.
As you can imagine, I'm a big fan of the flat patch cables that EBS and Rockboard introduced. They are a real game changer. They enable layouts that could never happen with bulkier cables and they don't suck tone.
These "flat" power cables are not in the same category. Compared to a few different off-brand right-angle power plugs, they either had the same or very slightly smaller height and cable diameter. Additionally, the piece of plastic that protrudes past the plug makes it hard to fit it through tighter holes, especially if you've already ran other cables through it. You actually have to damage the "compact" cable (aesthetically) so that it fits through holes where the power cables you probably already own fit.
Otherwise, it's a quality cable, well made, and available in different lengths, which can help you minimize the amount of cabling going on under the hood for aesthetics and ease of maintenance. This is why I'm not returning all of them. The price is not unreasonable, either.
They're also designed with a twisted copper shielding to minimize interference. I can't tell whether this is effective since I bought them along with a new power supply and didn't test them with the old noisy one.
But the marketing line that these are more compact than usual is nonsense. I'm probably on the extreme end of how much size matters, and even I don't find them to be a meaningful improvement in any way in this regard.
Which is a shame, because that's why I bought them. At least they aren't worse than the random ones I had. However, I am very much against misleading advertising, which is why I'm giving the product a lower rating than it deserves on its own merits.