When I started using strap locks as a standard upgrade on all my guitars some 10 years ago I aleays went with Schaller. They never failed and always felt like durable, high quality products.
I stumbled upon the Harley Benton locks by accident. After reading many positive reviews I decided to test them out myself. The design is identical to the Schaller. Which means that you can use these products together, if needed. The HB variants are surprisingly sturdy and rigid, considering they cost a fraction of the price of the Schallers. I've completely switched over to these HB locks since a couple of years back and am very happy with the product.