GS300 // Moondrop KXXS
Both are similar looking after the connectors till the drivers. Kxxs is the fancier shiny looking big brother while GS is looking worn with its Blon-esque (read odd) fit. Kx is .78mm 2 pinned Gs uses MMCX.
Both are ~ same in driving. My source was LG G7 + Tidal Hifi.
Kx > Gs in all sonic aspects. Kx sounds mature and full bodied compared to Gs. The only positive of Gs at vs Kx is the level of bass. Kx sound pounding in some tracks. Though its just for your liking one might not prefer this.
And last live recordings and soundstage depth height etc.. Kx gave me a grin 😈 while Gs is only sufficent at this parameters.