Having run the Beretta long enough to get a feel for it I think I am in a position to offer some opinion on a few things I think Beretta executed exceptionally well as compared to the other gun I am most familiar with, a Glock 22.
The slide stop/release on the Beretta is a work of art. It seems to be perfectly placed and is robust enough to offer sure activation even under the pressure of 20lb recoil spring.
I sadly cannot say the same for the Glock slide stop/release. It is still workable, especially on Gen4 Glocks where it seems to protrude a little more than on older Generations. Sure there are parts out there on the market to alleviate this issue somewhat, but Beretta comes with it out of the box.
The slide serrations on the Beretta 96D are superb. I understand this may not quite be the same with a FS or G model Beretta, but on the D model, the serrations are great. They seem to offer a much better purchase than the Glock serrations that are relatively shallow and spaced much further apart. I am sure there is some formula calculating perpendicular surface area contact to the hand that could explain it better than my words. I first realized how inferior the Glock slide serrations were when I started shooting a P226 which has serrations very similar to the Beretta.
And then there is one of Glocks greatest attributes, and also one of the most annoying. Polymer encased magazines!!! Glock magazines are probably some of the most durable on the market, but they are FAT, they don't like to fall free as quickly as their all metal counterparts, and they don't have much of a tapper at the top. All of this starts to create problems on the reload. It can be mitigated some with technique, but I have on more than one occasion had to wait on an empty Glock magazine to clear the mag well before I could insert a fresh one. I have found all metal magazines to be much more agreeable with the reload.
I am not saying I don't like Glocks, because I do. There are a lot of things Glock does well, but I am appreciating more and more some of the non-Glock attributes of other handguns.