I've got to admit I was kind of waiting on this one, and I'm surprised it took so long to show up.
The Beretta safety/decocker is exactly the same as Walther P38 developed in the 1930's, the millions of S&W Traditional Double Action (TDA) autos that have been produced since the 1950's, all the Ruger P-Series autos that have been made over the years, and of course the long line of Beretta 92/96 pistols made. I'm sure there are others that have followed this design, but I can't think of them off the top of my head. So I'd say there are lots of other guns that operated exactly the same.
The SIG on the other hand, while not knocking the design or the manufacture of that design, is I believe, a unique animal. Is there any other pistol on the market that puts their decocker where SIG does. SIG's design, is the one that "...is completely inverse in terms of how to use it compared to most any other gun".