I think reliability is the most important thing in duty, guns, and duty gun accoutrement.
Assuming the extensions or extended mags are reliable there’s also a point of diminishing returns where they change the balance I’m handling of the gun.
In my experience, the Sigg factory, 21 round magazines, and the Glock 17 with factory +2 are OK but the Glock factory 22 and 24 round magazines start to make the gun unwieldy if you need to fire one-handed, etc.