My friend that is a key mentor has two of them, and boy howdy I always wanted that. Back then (probably ~1979) I couldn't even afford to get checkering done on the trigger guard of my pistol, but it didn't cost anything to put my finger there. Since going to TDI in 2006 I sorta tried to break that habit but seems like as soon as the timer goes off that is where my finger lands. Maybe/probably I will never break the habit, maybe/probably I will just quit trying, maybe/probably there are other gains to be had elsewhere.