After more than 20 hours of burning and more in listening, I should say these hk10 are good iem... And not only for the price

They are balanced, in the good side, so not boring.
Everything is there : basses and sub basses are presents. Mid too, and maybe a little forward. Treeble are nice too and always without any peak.
I agree, GK10 haven't the best resolution and separation but nothing disturb my ears.
There are smooth with a ngood but not so big soundstage.
So I can listen to them for several hours, without any fatigue, even if I would prefer a little more dynamic.
I tried them with diffrents tips and cable, and, as said, the sound can change.
I kept the JVC dots.
For the cable, I use the rhyme.
I tried a mixed (silver and cooper) cheap cable and, even if I founded the mid more forward, I feel a little lake of resolution.
I also tried them with the TWS BT 20s pro and I didn't like it... Not enough detail and precision.
But it pairs well with the lotoo S1.
As the fit is near perfect, they became my EDC iem, with AP80 pro or lotoo S1, for summer.
Even if these are not my best headphones, I don't feel any lack when listening different style of music.