The Cougars are nice guns.
They are similar stylistically to the Beretta 92 and similar with controls, but in many ways they are very different designs. I think both designs are awesome, however.
The magazines are not interchangeable because the magazine slot is cut in a different spot. The 92FS uses a recoil system like the Walther P38 whereas the Cougar and the PX4 use a rotating barrel system. The cougar is more compact than the 92, but there is actually also a 92 compact if you wanted a true compact version of the model 92. The centurion has a shorter slide, but there is also the 92 Compact which has the shorter slide and a shorter grip. And then to complicate it further, there is the 92 Compact type M which is single stack instead of double stack for a thinner grip.
Beretta released the Cougar in 9mm, .357 sig, .45ACP, and .40 S&W. Then, they came out with the PX4, which is VERY similar in design to the cougar other than the polymer frame and different styling, and again, different magazines. I like the metal and the styling on the Cougar better, myself. When Beretta came out with the PX4, they sent all the machinery to make the Cougar to Stoeger in Turkey. Stoeger is a wholly owned subsidiary of Beretta.
The cougar (and the PX4) can be changed to decock only without changing major parts, whereas the 92 would require 92G slide or some machining.
Even though the Cougar is more compact than the 92, there is a compact version of the Cougar too. Beretta called it the mini-cougar, and the Stoeger calls it a Cougar Compact.
I bought a Stoeger Cougar. I found it, like my Beretta 92FS, to be a fantastic gun. My friend liked the Cougar so much though, that I let him have it since I didn't need two 9mms.
I think the Stoeger Cougar is one of the best values on the market. I got it for $350 and that was for the version with an accessory rail. And as far as I can tell, it's just as nice as my 92 and I think I maybe even shot it a little better.
But with the market the way it is, good luck finding one!
There might have been another gun Beretta made a long time ago that carried the "cougar" name, before they made the current Cougar, which might have had an open slide like the 92FS, but I'm not sure. If there was, I think it was a straight blowback design in a smaller caliber. If there was a Beretta that was at one time called a Cougar before the current Cougar, I think that might be a relatively uncommon gun. But that would have had the Beretta name, I think, rather than Stoeger. More common is the Beretta Cheetah, which also has an open slide. There was also the older Beretta 70 which I think was called the Puma. Pumas and Cougars are real similar cats, as far as the hissing variety goes.
