Seconded (thirded?). I have two S1 boards and haven't had the first issue with either of them. Suuuuper solid and surprisingly heavy, and no stupid bloated and buggy software required to use them!
I've purchased several Keychrons over the past 5+ years. Build quality always has been solid, but Bluetooth connectivity to PC was lousy. It's a common complaint with Keychron. Ironically, BT to Apple devices (MacBook, iPad Pro, iPhone) worked...