Glocks 3 safeties, firing pin/ trigger/ drop, are all sequentially disengaged as the trigger is pulled, and automatically re-set as the trigger re-sets.
I use the NY one trigger module on my Glocks, not necssasarily for added safety of the heavier pull, though it's a plus, but I actually prefer the pull it offers. The main difference between the Glock, even w/ the NY 1 (8lb) or NY 2 (12lb) & say a DAO Beretta is the length of the trigger travel to discharge.
With the Beretta, the trigger will travel approx. a full inch before discharge, almost all the way to the rear of the trigger gaurd. On a Kahr K9 the 71b pull is actually less than my Glock, but again, the travel to discharge is approx. one full inch. Glocks's is 0.5in.
That's the main difference to me as far as Glock triggers vs. DA revolvers, DAO pistols ect... I don't pretend to fully understand the functional purpose of the trigger bar safety, it would seem if you snag the trigger on something or otherwise depress the trigger that it is going backwards w/ the trigger itself regardless.
I feel Glocks are just as safe as the other designs mentioned, the things I personally would suggest people remember is keep your finger of the trigger & remember that Glocks trigger travel to discharge is approx. half that of most other designs. As a side note I also think the NY triggers heavier pull would seem to do more if the trigger were snagged than the trigger safety itself.
Best, long shot!