One reason for this popularity is a very successful design element. The 8000 series has the rear of the grip-frame shaped inwards to give the hand more reach to the trigger. Thus, it fits smaller hands better than its bigger, older brothers do. The chiefs like that because it reduces the chance of disparate impact lawsuits from female officers and other personnel with small hands who suffer occupationally because they can't qualify with a gun too big for them. It also fits the hand well.
Triggers are good as well.
This particular Beretta .40 isn't a famous classic like its older brother, but it has its share of devoted fans, who like it for good reasons. The Line Continues Some years ago, when Brian Felter was still with Beretta, I told him that I thought the ideal Beretta .40 would be a 92 Compact chambered for that round. The idea apparently caught on, and a .40 caliber double-stack 96 Compact with a short, easily concealed butt should be available at any moment. 11-shot .40 Beretta has yet produced. The Model 9000 is a gun that shows promise, but after seeing it in action, the jury is still out.