Glock makes a good pistol... They work, and tend to be reliable. I am not the biggest fan, but I do respect them for what they are.
But as far as doodads to "make the gun safer"... I'm not a big fan.
I am of the mindset, that if you are the type to not properly check for a clear holster and trigger guard when holstering your pistol... You are not going to properly use the "doodads" properly or consistently either.
That applies to manual safeties, grip safeties, riding hammers, "gadgets"... and basically anything that isn't an automatic passive device that requires no conscious thought to use/work.
I have read of an ND that happened when a person removed their jacket. They got a pull string or other part of the jacket caught in the holster, but it did not go off when they holstered the pistol... It did go off after, when they pulled off the jacket.
Basically... No doodad could have prevented that ND... Only proper procedure when re-holstering their pistol and ensuring it was clear first would have.
Seriously... While you might only have a split second to draw your pistol... You have all the time in the world to re-holster... Take the time to do it properly.