I got the Glock 39.
Because I perfer .45 calibered bullet launchers and it is smaller than my Glock 30, which equated to easier conceal carry.
Ammo can be reasonable obtain by ordering online.
As long as law enforcement uses/supports a particular caliber, it will not die out.
Currently, five state law enforcement agencies have adopted the .45GAP and they switched over in the last 1-3 years.
Since a majority of the law enforcement agencies that use it are on the East Coast, ammo can be easier to find and less expensive then in areas where law enforcement has not adopted it.