Agreed! They keep impressing me. I listened to some live performances through them Sunday morning, early when everyone was still asleep, and let me tell you...:They're capable of extreme detail! Startlingly so.
I also attribute some of this to what you mentioned. Having enough power on tap. The 'Magni is not the highest end amplifier at all, but you know what, it is competently designed and can dish out some current, since it uses a linear AC supply and has a larger output stage than a lot of cheap chip amps.
To further this point, I tried the Edition XS on a few more portable sources.
First, the onboard headphone jack on my HP Victus gaming laptop. It sounded fine, but the bass obviously took a hit. For the record, I use no EQ with my headphones.
Then I tried them on a Tecsun multiband radio which runs on battery power and only says it can push an 8-32z load. Not a lot of info there. This sounded pleasing on FM. It was a fun test. I feel it drove them fine, actually!
I'd like to hear one of the higher-end Hifimans someday. Such as the HE-1000.
At that level, I'd likely check out a lot of other brands too, though.