Thanks but I'm Asia haha.
And yeah, I managed to do an extensive comparison between the DX240 and M15s already.
In short the M15s is more dynamic and lively while the DX240 sticks close to reference as much as possible.
Bass wise the DX240 is more controlled and tighter while the M15s has a relatively looser and boomier bass which sacrifices detail. With the DX240 you get layers, with the M15s you get a single note if that makes sense. In most songs this may not be a factor but in songs with prominent bass melody it has a more congested feel to it.
Mids wise the M15s feels more forward while the DX240 sounds dryer. Detail levels are excellent on both but the M15s sounds livelier. I want to say that the M15s is almost coloured in a way compared to the DX240. But it's done more tastefully than say on the Cayin N7.
Treble wise, rather than saying the M15s is less extended, it would be better to say that the M15s has a softer presentation while the DX240 presents it as dead neutral. This difference is exacerbated if you turn on level 1 and level 2 second harmonic distortion control. So if you have something with harsher treble the M15s reels it back in, but on already rolled off gear the DX240 is better.
Soundstage wise the DX240 has a clearer but smaller soundstage but the M15s is just larger overall. Both are on par with instrument placement and holography.
Dynamics wise it's no contest, the M15s is much better than the comparatively flat DX240. Notes have more punch and weight compared to the dryer presentation on the DX240.
With the exception of the looser bass I would prefer the M15s over the DX240.
Overall I'd say the DX240 sounds like an upgraded and refined DX160 whereas the M15s brings better dynamics, wider soundstage and a livelier performance overall.
There is a caveat with the M15s that can be absolutely dealbreaking though. The heat.
Why did FiiO think this is ok? This can burn you if you keep your player in your pocket.
And I'm not even using its leather case so it's already a best case scenario. No wonder the M15s needed a 6k mah battery to match the battery life of the DX240. I'm just playing plain old 44.1khz flac by the way, I've yet to see the full extent of how bad it gets with higher resolution tracks.