I received my APP3 yesterday and have used them for several hours now. The FR (as I hear it) is vastly superior to the APP1, which severely cut off the top end when ANC was active. The APP3 has enough treble precision and extension to generate an actual soundstage, and imaging/localization is far better. It does have its limits, as I don’t hear the room and it seems to smooth over details.
Bass…it has the consumer boost profile. It doesn’t color the midrange much, so I’m okay with it for the use case. If active, working out, or in noisy places, the ANC improvement and cutting through the background is worth it.
In sum, I’m with @Argha on this one.