policy
Policy stated you would carry agency's issue pistol, which translated into several varieties of SIG. There was provision to carry a personal weapon, with supervisory approval, which must meet policy, so any PO handguns on duty were also SIG.
I bought an identical SIG so as to have a second gun should mine go down, or have to be surrendered for administrative reasons. I also shot my PO SIG, in my duty rig in IDPA, for more trigger time.
The duty SIG and its clone were big pistols, not easily concealed in some circumstances. Many, including myself, also bought a smaller SIG model (on the approved list) for off duty and backup carry.
All those guns had to go to the range, along with their carry system, for bi-annual quals, light and reduced light, pass fail on the spot. As a rule, the agency, nationwide, shot very well.