WRT the 92 series, some find the grip diameter too large, and the double action trigger reach too long. The trigger itself is fine, and the gun tends to go bang every time. Only mechanical headache is the locking block is subject to unannounced failure, locking up the gun in the process.
As far as police sales, Beretta initially sold well. However, a few factors have lead to a large loss in market share. The locking block replacement issue, combined with Beretta's announced withdrawl of support for the model in favour of new lines has pissed off not a few departments.
The second factor is external. Glock beat them wrt product support, and regular gun buy back programs have made for some pretty happy departments. Glock have replaced old guns for new at low cost, updating departments from first and second generation guns to the current model. Glock meanwhile can sell these old guns in markets like Mass. and California where there is a high demand but hurdles in the way of selling new product.