[DoctorStrange]

Glock 19 gen 5. Over 7000 rounds. Zero failure of any kind. All original parts. Had changed RSA once, as preventative maintenence.

That to me is the definition of reliability.

Double stacks tend to be bigger overall than single stacks. Bigger ( from a theoretical standpoint... at least in my mind) tend to be more robust..all things being equal. ( A pocket size 9mm vs. A full size 9mAm from the same manufacturer...)

But when it comes to Glocks...both single stacks and double stacks are superbly reliable. Any difference between the two would require so much ammo to test...that it would be a futile exercise.

Both will outlast most people.

Arguably though, with the average larger size and mass of a double stack, bigger grip, etc, one is less likely to limp wrist and so on. Again, on average. But, maybe I'm wrong.