I was all in with CR123 when I first got into this. For years my daily pocket carry was a small-as-they-get 2xCR123 light, which was fairly popular and common at the time (Surefire, Fenix, 4Sevens were mine). I even put a chunky 1xCR123 on my keychain (P1, then P1D-Q5). But not any more.
There...