This isn't a review of XS but Hifiman Arya Stealth version which I love quite alot, especially paired with my 2W hybrid tube amp Xduoo TA10.
Everybody praise gigantic headroom of these as well as imaging and clarity, and for good reason since its certainly the highlight, but the vivid sparkly treble is so fascinating too...give a read to my review for more details, it include comparison to Sundara and Sennheiser HD820
Pros:
-exceptional resolution
-exceptional imaging
-exceptional technicalities
-gigantic headroom
-holographic multi layered spatiality
-excellent transparency
-realist richly textured timbre
-fast, snappy and controlled attack
-can deal with busy track gloriously
-open airy crisp and delicate treble
-wide center stage and clear mid range
-impactfull and warm bass
-very comfortable (no hard clamping force and big ear cups)
-can take EQ and bass boost without distortion
-detachable cable
-swivable ear cups
-potent sound value under 1K$
Cons:
-not the most define or deep bass response
-a bit thin mid range
-treble can sometime stole the show
-source picky (transparent to source)
-need at least 1W of amping
-construction will OK isn't mind blowing for the price
-cheap cable
-underwhelming packaging
https://www.head-fi.org/showcase/hifiman-arya.23838/reviews#review-31095