First of all, the picture that you posted is not the "Duty" model, it is simply the Sphinx SDP Compact. The Duty version has a longer grip and uses 17 round magazines where the standard Compact uses 15 round magazines. If you look at the pictures of both on the Kriss website, you can see that the portion of the grip between the rubber grips and the magazine on the Duty model is longer than the Compact.
Second, the Duty model has a full all aluminum frame including the grip module. The Compact in the picture has an aluminum frame, but the grip module is made of a polymer material for weight savings. I believe that there were some models of the Compact that had the aluminum grip module but the picture appears to have the polymer. Go to the Kriss website and look at the pictures. On the Duty notice the machined vertical lines on the front portion of the grip, while the Compact version has more of a stippled looking texture.
When Kriss bought out Sphinx, they also bought out the existing parts supply so that when Kriss started assembling the Sphinx in the US in the beginning they used the Swiss manufacturer parts until the parts inventory was used up. From the pictures, it appears that the one you are looking at was built in Switzerland, but for a while anyway, you could have purchased a USA made Sphinx that still had "Switzerland" engraved on it even though it was assembled in the US . I'm not sure when the parts supplies were used up and the pistol was 100% assembled with USA parts, but perhaps you could contact Kriss and using the serial number, they could tell you for certain.
I have the US made all aluminum frame and grip module Duty version and it has been flawless. There are always those that say that the made in Switzerland model was built better, but that's open to interpretation.