I have Apex triggers (~4#) and thumb safeties in my Shields. If Glock made a thumb safety I would have it in my 19. A thumb safety is an added level of confidence that the weapon is not going to fire unintentionally. The little "safety lever" in the middle of the trigger is not really safe. Is a Glock 19 safer than a Sig P320 because of that little lever? And now the 320 is available with a thumb safety because our military wants it.

Just sayin...