-Long, positive track record for proven reliability.
-Built to endure a lot of use.
-At least the old ones are well built using minimum MIM parts.
-Very accuracy.
-FWIW, "tacticool" factor that some special forces units use them at times.
-Quite possibly could have been the sidearm that replaced the m1911 for the military if it was cheaper to manufacture and outfit the troops and armories than the Beretta was(American rifleman Dec 09).
Need I go on?