It definitely has the power to drive some of my earphones and headphones substantially past my normal listening level - for example my KZ ZST IEMs and my Sennheiser Momentum over-ear - and definitely louder than my MacBook Pro.
It also can power my harder to drive headphones, but not as powerfully, but with enough juice to satisfy my listening levels even on material mastered at lower levels.
It definitely doesn't distort or hurt my ears, though, which is something my FiiO X1 can do with low-impedance, highly sensitive earphones and headphones, so I agree it is doing something "different," for example, with "Remorse" by Sam Phillips, my FiiO X1 distorts slightly and is way too loud with my Momentum over-ears at max volume, but the Walnut is not quite as loud and doesn't distort them.
However, the Walnut is noticeably louder at max volume on that same song on the much harder to drive Beyerdynamic DT 880 250 Ohm headphones, than the FiiO X1 is, which renders the song with less volume.