I love my 219b sw35 swapped Thrunite Ti3. Nice moon mode for reading or long runtimes and great brightness on max off one AAA. I’ve tried those Rovyvon-style keychain lights but the side switch is a PITA on something that small so I’ll stay with a twisty. I also prefer a changeable battery not an integral one, especially in a low capacity light.
Honestly, I’d have a hard time passing up a high CRI, neutral tinted Photon Microlight if they ever released it. Yes, yes you can LED swap but I’m not thrilled with how floody the current 5mm LED options are.