I used to own the ASR Basis Exclusive (battery powered 2-box) and a Pass Labs Xono before that. I have yet to hear or see the XP15 and XP25.
Comparing the ASR to Xono, the ASR is quieter, more dynamic, better at timbre and more refined. The Xono does everything well, but nothing really outstanding. Hope this helps a bit.
At this price range, also consider the Whest Audio 30RDT and 30RDT SE. The SE is more revealing, more dynamic and higher resolving than the ASR Basis Exclusive. Which also means Whest is less forgiving of bad pressings and setup.
Comparing the ASR to Xono, the ASR is quieter, more dynamic, better at timbre and more refined. The Xono does everything well, but nothing really outstanding. Hope this helps a bit.
At this price range, also consider the Whest Audio 30RDT and 30RDT SE. The SE is more revealing, more dynamic and higher resolving than the ASR Basis Exclusive. Which also means Whest is less forgiving of bad pressings and setup.