Joe, my only experience was with a pair of slats I got from David Knight. I used them to beef up a 60" osage static recurve that I tillered out too soon after it was cut. The bow took excessive set and fretted pretty badly. I ground the belly flat and added the Argentine osage to the belly and retillered the bow. It worked out great. The only difference I could find between the two was the color. The Argentine osage worked like our US variety. The shade of yellow was the only difference that I could tell. David thought highly of it in BBO bows he made.