Reviewed the Earfun Air. It's brighter than Earfun Free, less bassy, better design quality.
Other comparisons:
Pamu Slide – strong fat bass with subtly clear treble, slightly better than Earfun Free, but Earfun Air is certainly offers brighter treble.
Redmi Airdots S – with almost similar tuning as the Earfun Air, but the treble is slightly more brittle and sharper. Overall, simpler build without all the fancy specs.
Ugreen HiTune – offering more balanced tuning with less forward treble compared to Earfun Air, overall tighter sound staging.
Creative Outlier Gold – the mid-treble (vocals) on the Outlier Gold is more prominent, the upper-treble (percussions) is less sizzling.