I have 3 audio phones ( Meizu Pro 6 Plus , Xplay 5S & Xplay 6).
I have 2 USB dongles ( S9 Pro & Link2 Bal ) & a Topping DX7 Pro.
I have a Spirit Pro , Listen Pro & Elegia.
While they sound awesome , i don't use Xplay 5S & 6 anymore.
Mainly because of the UI.
I use S9 Pro with Pro 6 Plus (plug & play) and Listen Pro.
I use DX7 Pro with Galaxy S7 (LDAC) and Elegia.
I didn't use Link2 Bal since i received it , but i think it would switch with S9 Pro to be use with Listen Pro.
While Xplay 5S may be the TOFL in audio smartphone segment , to me S9 Pro does everything XPlay 5S does , but better : soundstage , level of detail , neutrality ...
Really , you should take a look to
#donglemadness and find something that suit you taste in the TOP10 - TOP20.